SD File cannot be play in Plex

I have a movie file that cannot be play in Plex. I get an error saying:
This server is not powerful enough to convert video.

Playing the file in Windows directly via VLC is fine. What can I do to play it in Plex? I am running Plex with a RPI4.

Media
Duration 2:05:56
Bitrate 2204 kbps
Width 720
Height 400
Aspect Ratio 1.78
Video Resolution SD
Container MKV
Video Frame Rate NTSC
Video Profile advanced simple

Part
Duration 2:05:56
File God of Gamblers (1989) [Cantonese].mkv
Size 1.94 GB
Container MKV
Video Profile advanced simple

Codec MPEG4
Bitrate 1756 kbps
Language 中文
Bit Depth 8
Chroma Location left
Chroma Subsampling 4:2:0
Coded Height 400
Coded Width 720
Frame Rate 29.97 fps
Height 400
Level 5
Profile advanced simple
Ref Frames 1
Width 720
Display Title SD (MPEG4)
Codec AC3
Channels 6
Bitrate 448 kbps
Language 中文
Audio Channel Layout 5.1(side)
Sampling Rate 48000 Hz
Display Title 中文 (AC3 5.1)

There is no hardware transcoder support on the RPi. And even if, probably not for the MPEG4 codec.

I recommend you to use adequate hardware for your Plex server. An entry-class mobile phone cpu won’t do.

And even if, probably not for the MPEG4 codec.

Fixed. Converted file to H.264 using Handbrake.