I do not qualify to file taxes this year as I made under the amount required, if I do not file how does the govt. know how much i made to get my stimulus check?

[xmasbaby0]

Did you file a 2018 tax return?  If you did not file 2019, they use 2018.

[NCperson]

they also know you had income because of the social security tax withholdings on those earnings, even though you were not required to file a return, so you should be 'okay'.