Hello
i just ordered a course one the payment is done. it shows waiting for admin approval.
that course is made by the instructor not admin.
so you can see the attachment
It has nothing to do with the course creator .
this is payment confirmation and only admin has access to mark complete the order for the user from wp-admin -> woocommerce -> orders.
If you wish to change that text then you have to translate that by following this tip :
https://wplms.io/support/knowledge-base/translate-using-codestyling-localization-plugin/
there is no way to mark auto complete as there is stripe allows the payment
You can try using woocommerce auto complete orders plugin:
https://wordpress.org/plugins/woocommerce-autocomplete-order/
This will automatically complete the orders and you don't have to mark this again and again.