The way to collect any missed stimulus is to file your 2020 and 2021 tax return. As noted by others, look at Line 30 of the 2020 and 2021 tax return.
were you a dependent of someone else during those years? if yes, you are not eligible for the stimulus.
filing 2019 doesn't have anything to do with it.
Also, suggest checking your IRS transcript to see if they issued stimulus during those years and you simply didn't receive the check. if yes, the process is different. You have to contact US treasury using Form 3811.
https://www.irs.gov/pub/irs-pdf/f3911.pdf
the deadline to file the 2020 tax return to obtain the stimulus is May 15, 2024
