"Export Selected Brushes" Greyed Out

Hello,

I cannot manage to find an answer to this issue anywhere in the community or elsewhere.

I have created custom brushes that I want to export in order to paint digitally on Photoshop on other computers. However, when selecting the brush or brushes, the "export selected brushes" button is greyed out. I have tried restarting my computer and resetting the preferences on Photoshop, but nothing works.

I use Photoshop 2022 on a Mac OS Monterey.

I have attached a screenshot of the greyed out button.

I must note that the button is also greyed out on my other Mac which is running with the latest system.

Thank you in advance for your help!