Could not validate the domain when using OAuth

I use OAuth to support my project but i got some issues during creation.
I have already followed all the instruction, but the verification showed that “can not access the html file, please be sure the file uploaded correctly and retry”.

Are there any solutions to deal with these matters urgently?


Thank you for reaching out in relation to Our Domain Validation process, the next steps will be sent to you via DM. Please refer to our domain validation resource: Domain Validation Explanation for any further questions you may have about the process.

Thank you.