You mean, you want to apply for the extension of the MDD (Medical Device Directive 93/42/EEC) certificate according to
REGULATION (EU) 2023/607? You then have to formally apply for MDR certification (Regulation (EU) 2017/745) to your NB by
end of next week (Article 3c.(e)). Be aware that the formal application might take some time to lodge. That means, you're very likely too late now if you haven't applied already.
Depending on the class, additional conditions might apply.