When I test this TC on preview the button is not working and I see console log error:
category.js:878 Uncaught TypeError: Cannot read properties of null (reading 'set')
setNotification @ category.js:878
followCategory @ follow-category-button.gjs:37
(anonymous) @ d-button.gjs:136
invoke @ index.js:264
flush @ index.js:180
flush @ index.js:334
_end @ index.js:762
end @ index.js:565
_runExpiredTimers @ index.js:869
setTimeout
setTimeout @ index.js:39
_installTimerTimeout @ index.js:912
_reinstallTimerTimeout @ index.js:896
_later @ index.js:829
later @ index.js:652
T @ index.js:562
_triggerAction @ d-button.gjs:133
click @ d-button.gjs:91