Not able to attach/add files to websites

I am not able to attach/add files to websites. Whenever I go to photos folder it is shown as gray and I am not able to enter it. Can it be with access rights to do?

I use mac air M1.

other files are not accessible for attachments as well. For example files from downloads are also shown in faded gray, but can not be attached to this post (neither photos)

Do you know how to solve this issue?