How to increase max upload file size for restrict users?

Hello, I have plugins that make a restriction for users, one of the users can only post articles, they are not admins. The problem is that these users with access restrictions they can’t upload files in their posts larger than 1MB, how can you help me with that?

Please don’t tell me to configure PHP or HTacess as I’ve already done it there and increased it but unfortunately users with restriction can’t upload files larger than 1MB.

The page I need help with: [log in to see the link]