WOrk permit

Hello! I was able to get a z visa last month but because of plane ticket cost, I’m unable to come back just yet. My work permit is expiring in a month. Can my employer still extend it without a valid residence permit? Can they use my z visa to apply for WP extension? I’m afraid I have to re-apply for a new one once my WP can’t be extended on time. That would mean more documents to prepare and submit.
Thank you!