I did not receive the 3rd stimulas nor did i get the recovery rebate credit. How do I get it.

Sorry--it is too late.  The deadline to file a 2021 return to seek the recovery rebate credit was April 15, 2025.

The IRS issued three stimulus payments (two in 2020 and one in 2021). It's too late to claim the Recovery Rebate Credit for 2020 and 2021. The IRS began issuing payments to eligible people who didn't claim the Recovery Rebate Credit on their 2021 tax returns, so you don't need to do anything to get these payments.

Review the IRS website Recovery Rebate Credit for more information. 

The deadline for a 2021 refund is Postmark today, April 18th 2025 unless you filed for an extension of time for your 2021 tax return.. If you put it in US Post Office mailslot today before collection time, it should work.