Salesforce return URI with code value automatically truncates additional parameter

When return URI is set of Salresforce and when actually redirected to Salesforce, Code parameter is automatically removed but when set parameter as c__code then it retains the value. Can we alter the code parameter name to c__code or any other solution can be considered?


Detailed Issue description which may be helpful to understand this issue better:
Scenario : We are trying to implement authentication flow which is initiated from Salesforce and get login page and provided credentials are authenticated against authentication provider which is configured with Auth0, upon successful authentication user gets redirected to salesforce with additional parameter code.

Issue : When redirecting to Salesforce with code parameter, salesforce removed any parameter after ? and so the code parameter is removed. One workaround for this fix is to send code parameter as c__code which seems to be not possible from Aoth0 end.

Example :

Expected return URI:<<<>>>

Actual returned URI:<>

Which gets converted to when Received in Salesforce:

is there is any way to send code parameter with some name which starts with c__? Or any other workaround which can be considered in this scenario.