According to the BIR Revenue Regulation 08-2018:
"If the taxpayer is unable to timely update the required registration, s/he shall continue to file the percentage tax return reflecting a zero-amount of tax with a notation that s/he is availing of the 8% income tax."
You have until April 25 to do so.
Do take note, however, that different RDO's seem to implement this ruling differently. Some require that you change your RDO and won't accept the forms as written in the RR. So, it's best for you to check with your RDO to make sure you're following a process that they accept.