@Robert **********
if you are leaving Thailand and you have whatever requirements your airline or destination country require (RT-PCR COVID test results etc).... Then YES you can pay your overstay fine on departing BKK.
In that case I would not recommend you mention the reason why you overstayed...
They are not going to waive the overstay fine accrued.
May cause you to be placed in detention until the incubation period of 15 days is over...
Up to you... This question has been not been asked before.