ITR 1 or ITR 4?

Hi friends ,
my friend is a salaried person in one of the company and also he has a separate small scale business where he is the proprietor and he holds a GST number which is same PAN number which is linked to his salary account and his annual salary from his company is 3 lakhs 2018-2019 and his turnover including profit from his proprietorship is 2 lakhs for 2018-2019.
should he file itr 1 and itr 4 or only one of them.

he has confusion filing the tax returns, please help.