Is it possible to disable http/2 by connecting SSL?

Question

Nginx

Hello!
On the side of the reg provider in the selected hosting, there is a limit on the number of http requests.
Access to nginx is not granted, is it possible to force the site to work only on http/1?
It's just that there are pages where a part is not loaded in the developer console in the waterfall column, it is clearly visible that http / 2 requests are sent to the hosting at the same time and just a part gets 503, for http / 1 sequentially and this is visible in the waterfall and all 200 OK.
Is it possible to set this in the .htaccess file?

Found such an option, it denies the generated HTTP protocol in the request version 0.9, 1.0 and 1.1 only[403].
RewriteCond %{THE_REQUEST} !^[AZ]{3,9}\ .+\ HTTP/(0\.9|1\.0|1\.1) [NC]
RewriteRule .* - [F,NS,L ]
Changed to version 2 did not work.

Answer 1

Nginx only reads the main config and what is included there. So, if the hoster has not provided any user access to the configuration, then nothing.
https://nginx.org/ru/docs/beginners_guide.html
https://nginx.org/ru/docs/ngx_core_module.html#include
Is there a file equivalent of .htaccess for nginx and lighttpd?
Could the underloading problem be caused by something other than http/2 ? http links on https pages are not mixed?

Answer 2

Change hosting. Hosting from registrars has never been of good quality.