What are the requirements and potential issues for extending my stay in Thailand with a COVID extension?

Hello!

I went to an immigration office because want yo know what can I do for a stay extension. I’m Peruvian, have 90 days (until july 23rd) and I don’t need a visa. They told me that I can apply for a covid extension (60 more days) for 1900 bahts. I have a couple of questions about that and maybe here you guys can help me:

1 - It’s pretty much sure to do that? I mean, I need to give them an explanation or they are giving them just “if you pay the fee”?

2- This is the most important one: Can I have any problem if after those 60 days I go out for a week and then come back to Thailand?

Thanks for the time!