Running Rest API in Power query on each object

Ref - https://docs.microsoft.com/en-us/rest/api/power-bi/

GET https://api.powerbi.com/v1.0/myorg/groups/{groupId}/dataflows 

If I use the above in web connector in a poewer query, gives me all the dataflow details from my workspace.

Now, I want to run 

GET https://api.powerbi.com/v1.0/myorg/groups/{groupId}/dataflows/{dataflowId}/datasources

for each of the df object returned in the last step, so that I can get the datasources for each of my dfs returned in a single table, in a single query.

This is what I tried so far, created a custom function called getDF_DS to run on each DF object

/*custom function called getDF_DS*/
(x as any) => let        
        Source = Json.Document(Web.Contents("https://api.powerbi.com/v1.0/myorg/groups/xyz/dataflows/"&x&"/datasources", [Headers=[Authorization="Bearer reallyLong"]])),
        #"Converted to Table" = Table.FromRecords({Source}),
        #"Expanded value" = Table.ExpandListColumn(#"Converted to Table", "value"),
        #"Expanded value1" = Table.ExpandRecordColumn(#"Expanded value", "value", {"datasourceType", "connectionDetails", "datasourceId", "gatewayId"}, {"value.datasourceType", "value.connectionDetails", "value.datasourceId", "value.gatewayId"}),
        #"Expanded value.connectionDetails" = Table.ExpandRecordColumn(#"Expanded value1", "value.connectionDetails", {"server", "database"}, {"value.connectionDetails.server", "value.connectionDetails.database"}),
        #"Changed Type" = Table.TransformColumnTypes(#"Expanded value.connectionDetails",{{"@odata.context", type text}, {"value.datasourceType", type text}, {"value.connectionDetails.server", type text}, {"value.connectionDetails.database", type text}, {"value.datasourceId", type text}, {"value.gatewayId", type text}})
    in
        #"Changed Type"

let
    Source = Json.Document(Web.Contents("https://api.powerbi.com/v1.0/myorg/groups/xyz/dataflows", [Headers=[Authorization="Bearer longStringHere"]])),
    #"Converted to Table" = Table.FromRecords({Source}),
    #"Expanded value" = Table.ExpandListColumn(#"Converted to Table", "value"),
    #"Expanded value1" = Table.ExpandRecordColumn(#"Expanded value", "value", {"objectId", "name", "description", "configuredBy", "users"}, {"value.objectId", "value.name", "value.description", "value.configuredBy", "value.users"}),
    #"Changed Type" = Table.TransformColumnTypes(#"Expanded value1",{{"@odata.context", type text}, {"value.objectId", type text}, {"value.name", type text}, {"value.description", type text}, {"value.configuredBy", type text}, {"value.users", type any}}),
    #"Removed Columns" = Table.RemoveColumns(#"Changed Type",{"value.users"}),
    #"Filtered Rows" = Table.SelectRows(#"Removed Columns", each ([value.configuredBy] = "[email protected]")),
    #"Added Custom" = Table.AddColumn(#"Filtered Rows", "Custom", each getDF_DS([value.objectId]))
in
    #"Added Custom"

It returns following

Expression.Error: Access to the resource is forbidden.

But let's suppose the Bearer "reallyLong" was generated for dfID=123 and I perform a filtered query like below it works, like below

let
    Source = Json.Document(Web.Contents("https://api.powerbi.com/v1.0/myorg/groups/xyz/dataflows", [Headers=[Authorization="Bearer longStringHere"]])),
    #"Converted to Table" = Table.FromRecords({Source}),
    #"Expanded value" = Table.ExpandListColumn(#"Converted to Table", "value"),
    #"Expanded value1" = Table.ExpandRecordColumn(#"Expanded value", "value", {"objectId", "name", "description", "configuredBy", "users"}, {"value.objectId", "value.name", "value.description", "value.configuredBy", "value.users"}),
    #"Changed Type" = Table.TransformColumnTypes(#"Expanded value1",{{"@odata.context", type text}, {"value.objectId", type text}, {"value.name", type text}, {"value.description", type text}, {"value.configuredBy", type text}, {"value.users", type any}}),
    #"Removed Columns" = Table.RemoveColumns(#"Changed Type",{"value.users"}),
    #"Filtered Rows" = Table.SelectRows(#"Removed Columns", each ([value.configuredBy] = "[email protected]")) and ([value.objectId] = "123")),
    #"Added Custom" = Table.AddColumn(#"Filtered Rows", "Custom", each getDF_DS([value.objectId]))
in
    #"Added Custom"

Does it mean, that I need to generate Bearer value for each DFs and run seperate queries with seperate Berear values on corresponding Dfs? It defeats the purpose.  Is there a workaround

End Goal - I am trying to create a dependency map between dataflow and datasource. We have so many dataflows, lineage view is just not practical for us. Once I have the depency mapping I want to create a custom viz that would work for us in a network map/tree like structure.

Any help is greatly appreciated.

ImkeF  nickyvv