Help needed with M query

[PBISQL]

I've used GraphQL API to establish a connection between Power BI and Monday.com. I can now access the main board, however, every task on the main board has got its own separate board (specified in 'Link' column - Exhibit A). Now, I'm trying to find a way to automatically import every of the aforementioned boarda by using the URLs in the 'Link' column.

I've been using this solution to solve my problem, however, the moment a try to use a custom function in order to modify my perfectly working M code (exhibit B) I get an error (Exhibit C, D, E). I'd really appreciate your help!

(Exhibit A)

Exhibit B (if I manually specify board ID the query will work just fine)

Exhibits C, D, E (if I create a custom fuction (LGA) in order to feed board IDs through a parameter my function the query will stop working)

After enerting a board ID i get this error.