The IRS shows they already sent it to you.
Double check your bank statements and Check your IRS account (both accounts if married)
Your Online Account | Internal Revenue Service
If the IRS thinks they sent it to you but you didn't get it request a trace for a missing third Stimulus payment
https://www.irs.gov/newsroom/questions-and-answers-about-the-third-economic-impact-payment-topic-j-payment-issued-but-lost-stolen-destroyed-or-not-received
Did you get IRS letter 6475? That is telling you how much they sent you. If you are married you each get letter 6475 for half.