It depends how many there are - if there are only a few then manually fetch them all in GSC and request a crawl one by one.
If there are many you could create a page with them all listed as hyperlinks and perform a fetch with using "Crawl this URL and its direct links"
They should be back in very soon. It's difficult to gauge the impact. If all internal linking and backlinks are still in place you there may be minimal damage if any.