YaCy / nginx - 504 Gateway Time-out

Hello all,

I need some help with YaCy - but maybe it is quite simple and it s just about nginx.

My YunoHost server

Hardware: VPS bought online
YunoHost version: 11.2.12 (stable)
I have access to my server : Through SSH and through the webadmin
Are you in a special context or did you perform some particular tweaking on your YunoHost instance ? : NO
If yes, please explain: NO
If your request is related to an app, specify its name and version: YaCy 1.924~ynh2

Description of my issue

It is about the APP YaCy. During various actions, such as displaying a large index of a crawled URL with a lot of content, nginx timeouts occur:

504 Gateway Time-out

Is it possible to set the value for TimeOuts high for the nginx? For example in /etc/nginx/conf.d/mydomain.com.d/yacy.conf?

Do you know anything or have any tips for me? That would be great.
Thank you and best regards