413 request entity too large – Web API

I’m running into a 413 issue while trying to send data from my web application (.netfx 4.6.1) to my web api (.net core 3.1). In the code below, I send a list over containing byte data of images along with additional data needed to build a file. The expected output is to return a byte array containing the new file. Unfortunately when sending the request I receive an error: Response status code does not indicate success: 413 (Request Entity Too Large).

To use or not to use Data transfer objects(DTO) in a Web Api Chat Application Backend Server

I have a chat application backend built using Web Api where I am exposing several database entities directly to clients. I was wondering whether there is any positive points to map the entities to DTOs or should I continue exposing the entities as I am currently. Just to clarify I am not asking a DTO vs non-DTO general question but just advantages of using it in this scenario since most of the fields in the entities would probably be used by the client.

check user validation in Asp.net core with jwt authorization

I implemented Microsoft Identity and JWT in my web api,
a client can login and get a JWT token and store it in the application.
since the expiration of the token the user can access the the server,
but if I remove a user from my database, the removed user still has its token and can access the web api,
how can I check the validation of the user?