Is it better to send data from server before rendering or to perform API calls client-side?

I have a simple question, I have a complex web app to develop, and I hesitate between two concepts :

1. When a server recieves a GET on a page, it makes all the SQL requests, and renders the EJS page, giving all data as an argument.

2. When a server receieves a GET on a page, it simply renders the EJS page, but the scripts associated to that page (jQuery) will make the needed requests to my server’s REST API, rendering the result afterwards.

How is it usually done in the web dev world ?

Thanks for your help