File size limit of 25Mb

after created a new project, i committed and push my design. The error came back with
remote: GitLab: File "filexyz "is larger than the allowed size of 25 MB.

Git doc recommends as shown below, but i can not find Main menu > Admin in my project root. please help

The maximum file size for attachments in GitLab comments and replies is 10 MB. To change the maximum attachment size:

  1. On the top bar, select Main menu > Admin.
  2. On the left sidebar, select Settings > General, then expand Account and limit.
  3. Increase or decrease by changing the value in Maximum attachment size (MB).