It doubts sec 44ada person

1.assessee new scheme as per sec 44ada it returns filed in f.y.20-21.
2.A doctor maintained a clinic another doctor treatment in clinic some fees amount paid to another doctor.
question:
1.f.y.21-22 new scheme compulsory or old scheme accepted
2.fees paid to another doctors amount debited to fees collections account or visiting doctors fees paid account debit correct procedure.