Why we can not upload more than 130 000 kb ??

Server "upload_max_filesize" is 130 000 kb ?

Then contact your hosting support and ask them for more Server "upload_max_filesize"

The number of uploaded videos doesn't affect your site speed. It shows HTML5 Video Player in posts, when you click to see videos it initiates loading of video, so it's not loaded on page view.

https://gvectors.com/wp-content/uploads/2016/12/wpForo-Advanced-Attachments-in-post-content-video-audio.png

And please read the addon description before buying (scroll down and see the Description tab). For the videos it only supports HTML5 Video Player formats (MP4, WebM, Ogg): https://www.w3schools.com/html/html5_video.asp

Question : so with this i upload videos on my website ? So if i want to upload 15 Go of videos, i need an hebergement adapted ? 

And, my website will be slower than before if i add 15 go of videos ? 

You can do that with wpForo Advanced Attachments

I would like to propose videos in forum. 

I know there is a addon "embeds", but i don't want people can see the source (youtube etc...). 

I want that people can only see the video like if she was uploded on the website

Do you knwo how i can do it please ? 

Thank you