Doubt about registration for e invoice- reg

Sir,

As the turnover of FY 2017-18 exceeds the limit specified for e invoice, XYZ company required to be registered for e invoice from
01,04.2021.But as there were no sales during 2021-22 due to (temporarily) closure of company, it didn't get registered for e invoice. In 2022-23, It restarted business operations. So far, there are some only B2C cash sales. So far, there is no any B2B transaction.
Is it required to get registered for e invoice immediately
OR
Is it not required to get registered for e invoice and wait till it does B2B sales.
Kindly advise me.