Disabling HTTP2 on NextCloud with TRUENAS

[Skely]

Hi guys, I am new to TrueNAS and just got it installed yesterday, I am currently stuck in the upload speed limit in NextCloud which is a 200Mbps cap, it's not a hardware issue as when I upload to TRUENAS pool, I can reach 1000Mbps, which is the max limit of my machine. NextCloud forum says remove http2 from nginx config could fix it. But I am new to this and I don't have an idea about this, can anyone guide me? Any help will be appreciated. Thank you!