Ok ... you are talking about different 2 things ... the requirement to file a return and what to report on an income tax return.
Now if you are below the filing requirement for your filing status you are not required to file a return.
But if you are required to file then all income from all sources must be reported.
For 2021 ... even if you are not required to file you may want to file to get back any taxes withheld and/or any refundable credits you are eligible for like the CTC & EIC.
