Thank you for contacting the support.
The best approach for out-of-stock products is to keep them indexed and update the meta tags, and Schema markup with relevant data, so that when the product comes into stock again, you do not have to work on it to get it indexed.
Rank Math automatically updates the meta tags and Schema markup based on the product availability.
For a few other approaches and details, please have a look at this article: https://www.searchenginejournal.com/seo-temporarily-out-of-stock-product-pages/425242/
Hope this helps.
but i dont want to show out o stock products to my website visitors. so in that case, what should i do?
In this case, you can redirect the out-of-stock product pages to a relevant product on your site.
You can also check the following blog post for how to best handle discontinued products: https://www.goinflow.com/blog/manage-stock-products-seo/
I hope that helps.
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.