Imagine a tcode that you can't execute because of your roles/authorizations.
If you have permission to execute Function Modules (SE37 or SE80) you’re good.
Remember that this is a way to cheat SAP roles/authorizations, use at your own risk.
Run FM RS_HDSYS_CALL_TC_VARIANT and fill the TCODE you want to execute, then clear the AUTHORITY_CHECK field and execute.
The result is your needed TCODE :)
