Garantee one delegate call

Hi, i want know is my idea is ok from you experience and perspective:

i have some delegate, witch call external rest. I need call this rest only one time (it is legal operation with government), even token can cross this delegate many times for some reason. This external rest sometimes fall and didn’t answers, so my activity fall to incidents.

For make sure i call this rest only one time and it was happy call, in the delegate a set process variable like “ActivityNameCalled= true”. And in incidents i set variables like “ActivityNameCalled = false” (becouse i can fall to incident in many ways). In delegate i check this variable to false or null before call.

Is this normal way or you can advice more easy or maintainfull solution for that case?

I have some confusion, because i have some retries before fall in incident, so i there can be some problems for my approach