What is the resolution size for the avatar?

hey guys,

I am new here and wanted to add a avatar. but I keep getting the message

upload too large

i used png and jpg both with 350x350 and 100x100 resolution which were smaller than 100 kb. all four options failed

can somebody please enlighten me how I can upload an awesome picture of mine

the endpoint response of https://lemm.ee/pictrs/image returns response code 413 with

413 Request Entity Too Large

<center><h1>413 Request Entity Too Large</h1></center>
<hr><center>nginx</center>

as far as I can tell is maybe the some headers are missing from my side I do not know what the backend does.