Failed to update data source credentials - API call request

Hey Everyone,

I've tried my best to look up for a solution (same error was posted in https://www.pbiusergroup.com/communities/community-home/digestviewer/viewthread?MessageKey=7da6b52f-769c-4d71-b865-855f62da359e&CommunityKey=b35c8468-2fd8-4e1a-8429-322c39fe7110&tab=digestviewer but no answers at the end) to the below error on Power BI Service

I am currently running the query below to obtain an access token and utilize it on another URL to authorize and obtain the result I need.

let

GetJson = Web.Contents("https://login.***",
[
Headers = [#"Accept"="application/json",
#"Content-Type"="application/x-www-form-urlencoded;charset=UTF-8"],
Content = Text.ToBinary("grant_type=client_credentials&client_id=***&client_secret=***"),
RelativePath = "/realms/***/protocol/openid-connect/token"
]
),
FormatAsJson = Json.Document(GetJson),
#"Converted to Table" = Record.ToTable(FormatAsJson),
access_token = #"Converted to Table"{0}[Value],

source = Web.Contents("https://client-api.***/checklist-templates", [Headers=[Authorization="Bearer "&access_token,ContentType="application/json"]]),
Result = Json.Document(source),
#"Converted to Table2" = Record.ToTable(Result),
#"Expanded Value" = Table.ExpandListColumn(#"Converted to Table2", "Value"),
#"Expanded Value1" = Table.ExpandRecordColumn(#"Expanded Value", "Value", {"id", "name", "versions"}, {"id", "name.1", "versions"})
in
#"Expanded Value1"

and below are the two data source credentials that are generated from publishing the report

1. 

2. 

What am I doing wrong that PBI Service refuses to connect to the data source?

Cheers