44AD - Client forget to file return on PY 18-19,?

hello all,

As per section 44ad if a person do not take scheme of presumptive basis for continuous five year then he is not eligible for presumptive scheme for next 5 years from the previous year in which return is not filed according to 44ad.
and as a consequence of these the client has to maintain the books of accounts as per section 44aa and get his books audited as per section 44ab.

now my question is :
my client forget to file the return ITR-4 of previous year 2018-19.
can he file his income as per section 44ad in previous year 2019-20 or he has to get his accounts audited ?

shivam sood
ph no : 9781442245