Getting data from current sheet not working with excel.CurrentWorkbook()

Hello, I am trying to use power query to create a table from multiple sheets in a workbook, and the end goal is for my colleagues to be able to use it themselves as well, so in the query, I tried using excel.CurrentWorkbook as the source, but it will give this error. I do not really understand what I am doing wong as it is supposedly pointing to the existing table, so if you can help me, it would be much appreciated!

---------- Message ----------
[Expression.Error] The key didn't match any rows in the table.

---------- Session ID ----------
07c2dca4-458c-4f68-8d60-5edc4c44cc7d

---------- Mashup script ----------
section Section1;
shared MainRaw = let
  Source = Excel.CurrentWorkbook(),
  Navigation = Source{[Item = "MainRaw", Kind = "Sheet"]}[Data],
  #"Promoted headers" = Table.PromoteHeaders(Navigation, [PromoteAllScalars = true]),
  #"Changed column type" = Table.TransformColumnTypes(#"Promoted headers", {{"Source", type text}, {"Week Of", type date}, {"Sub Tactic", type text}, {"Market (New)", type text}, {"Tactic.", type text}, {"T1 Month", Int64.Type}, {"Month", Int64.Type}, {"Date + T-1", type date}, {"Comparison", type text}, {"Week (Monday First)", type text}, {"Brand", type text}, {"OS (Ad Set)", type text}, {"Market (New)2", type text}, {"Tactic (New)", type text}, {"Campaign ID", Int64.Type}, {"Campaign", type text}, {"Ad Set ID", Int64.Type}, {"Ad Set", type text}, {"Date", type date}, {"Spend", type number}, {"FB Installs (28 Day click + 1 Day View)", Int64.Type}, {"CPA: Mobile App Installs", type number}, {"Installs (Branch + SKAN) ", Int64.Type}, {"Branch/FB Installs", type number}, {"Purchases (App) (28 Day Click + 1 day View)", Int64.Type}, {"Revenue - Android (28 Day click + 1 Day View)", type number}, {"MULTIPLIER", type number}, {"24m LTV (28 Day click + 1 Day View)", type number}, {"24m ROAS (28 Day click + 1 Day View)", type number}, {"Impressions", Int64.Type}, {"Link Clicks", Int64.Type}, {"CTR (Link Click-Through Rate)", type number}, {"CTI (Android FB Installs/Link Clicks)", type number}, {"CPM", type number}, {"fb_mobile_initiated_checkout (App)", Int64.Type}, {"fb_mobile_content_view (App)", Int64.Type}, {"fb_mobile_search (App)", Int64.Type}, {"Conversion Event", type text}, {"T-1 Installs", type any}, {"T-1 24m LTV", type any}})
in
  #"Changed column type";
shared #"T-1 Raw" = let
  Source = Excel.Workbook(File.Contents("/Users/pdemirci/Desktop/EG MAI T-1 Daily Report.xlsx"), null, true),
  Navigation = Source{[Item = "T-1 Raw", Kind = "Sheet"]}[Data],
  #"Promoted headers" = Table.PromoteHeaders(Navigation, [PromoteAllScalars = true]),
  #"Changed column type" = Table.TransformColumnTypes(#"Promoted headers", {{"Source", type text}, {"Week Of", type date}, {"Sub Tactic", type text}, {"Market (New)", type text}, {"Tactic.", type text}, {"T1 Month", Int64.Type}, {"Month", Int64.Type}, {"Date + T-1", type date}, {"Comparison", type text}, {"Week (Monday First)", type text}, {"Brand", type text}, {"OS (Ad Set)", type text}, {"Market (New)2", type text}, {"Tactic (New)", type text}, {"Campaign ID", Int64.Type}, {"Campaign", type text}, {"Ad Set ID", Int64.Type}, {"Ad Set", type text}, {"Date", type date}, {"Spend", type any}, {"FB Installs (28 Day click + 1 Day View)", type any}, {"CPA: Mobile App Installs", type any}, {"Installs (Branch + SKAN) ", type any}, {"Branch/FB Installs", type any}, {"Purchases (App) (28 Day Click + 1 day View)", type any}, {"Revenue - Android (28 Day click + 1 Day View)", type any}, {"MULTIPLIER", type any}, {"24m LTV (28 Day click + 1 Day View)", type any}, {"24m ROAS (28 Day click + 1 Day View)", type any}, {"Impressions", type any}, {"Link Clicks", type any}, {"CTR (Link Click-Through Rate)", type any}, {"CTI (Android FB Installs/Link Clicks)", type any}, {"CPM", type any}, {"fb_mobile_initiated_checkout (App)", type any}, {"fb_mobile_content_view (App)", type any}, {"fb_mobile_search (App)", type any}, {"Conversion Event", type any}, {"T-1 Installs", Int64.Type}, {"T-1 24m LTV", type number}})
in
  #"Changed column type";
shared Append = let
  Source = Table.Combine({#"T-1 Raw", MainRaw})
in
  Source;