I can't verify my domain

[António]

I bought a domain for my shopify store but shopify is asking me for a TXT Record verification, unfortunately when I copy the code, paste it in the content box for the TXT Record, shopify tells me the verification has failed dispite the fact that I'm adding the record correctly. The only reason I could find for this is that the website I'm using for the domain control asks me to add brackets in the "content" section I refered before. Could someone help me with this please?