What should my husband do about his visa situation in Thailand following the visa amnesty extension?

Dear all,

Need some advice on the Visa Amnesty extension. My husband used to work in Thailand but has moved to another location but his work permit was not cancelled till we cancelled it in April before it expired .He was able to enter Thailand with this work permit in March and is here since then. With the amnesty extension till 26th of September, will he have to file for a 90 day permit and if so can this be done online ?

He is waiting for a flight to go back to his work location but as of now there are no flights and we are hoping that he will get one by the first week of September.

Would appreciate your help with this.