Why is Google Search Console showing a Server Error (5xx)?

[afzalsaleem]

Our website is on Shopify, and we received a "Server Error (5xx)" error on Google Search Console. After that, our 600+ pages were de-indexed.

Can anyone please explain this Server Error in the Search Console? We didn't see any issue on our hosting/server side. Everything was fine there.
Here is the website link
https://buyvitamins.pk/

I have also attached a screenshot of the Google Search Console. Any help or guidance will be appreciated.

Thanks