How can i add TXT Record into my domain?

[JxstErg1]

Only if your TXT record is an SPF record: if that’s the case, of course. If that’s not the case, maybe it’s better if you have a custom domain I guess; here are some websites you can get one for free:

Where do I get free domains?

You can try using EU.org or PP.UA (the latter one if you have a credit card even with a few cents on it and a phone number to use for verification, though the credit card is used only once for verification and then what’s free will remain free) as a valid alternative to Freenom (and Dot TK because Dot TK and Freenom are the same) that also supports Cloudflare and other things that Freenom with its domains supported.