Not sure yet how to solve this but I've got 3 main questions:
1. Your calculation:


With only Tire Option A AND 0 STOPS it would take 120sec*77Laps+0,027*exp(0,2315*77laps)=1498189 seconds
According to your chart y axis label: Time Loss Per Lap [sec/Lap]
the 0,027*exp(0,2315*77laps) part is for the added time for the 77th lap only, which is 1488949. The time added for the 76th lap would be 1181247 secs. So I don't think your calculation times for the whole 77 lap race are correct.

2. Of course, for Tyre A option the trendline is way out; your data shows 12 secs added fo the 30th lap, but the trendline is showing about 27, and it only gets worse with greater lap numbers. You get a better fit with a Power trendline or possibly the 2nd order polynomial.
Should we change that?

3. What version of Excel are you using? More specifically, which of the following can you use as part of a formula in a cell:
=SEQUENCE
=LAMBDA
=VSTACK

Finally, have you posted the same, or very similar, question elsewhere?