Eric SIMBOZEL thank you. We are glad to know that the API is useful for you.
Answering your question. Just create a JSON file with your own overrides and/or rules. See examples on Github: https://github.com/microsoft/sql-server-samples/tree/master/samples/manage/sql-assessment-api (have a look at DisablingBuiltInChecks_sample.json and MakingCustomChecks_sample.json, and also the tutorial ADS notebook and json samples coming with it). Once you make your own JSON file, run the following if your customizations are for SQL Instance:https://github.com/microsoft/sql-server-samples/blob/master/samples/manage/sql-assessment-api/MakingCustomChecks_sample.json
Get-SqlInstance -ServerInstance '<SQLSERVERINSTANCE>' | Invoke-SqlAssessment -Configuration '<FULL PATH TO YOUR JSON FILE>'
Or/and run the following, if your customizations are for SQL Database:
Get-SqlDatabase -ServerInstance '<SQLSERVERINSTANCE>' | Invoke-SqlAssessment -Configuration '<FULL PATH TO YOUR JSON FILE>'