Sorry about that those are fairly old commands (and if I’m being honest quite a mess). These ones should do the trick and be much easier to add for future users.
!add
$(urlfetch $(eval B=`https://twitch.center/customapi/`;Q=`quote?token=PRIVATE_TOKEN&data=`;S=`&silent=1`;X=parseInt(decodeURIComponent(`$(querystring)`));N=`$(urlfetch https://twitch.center/customapi/quote/list?token=PUBLIC_TOKEN&no_id=1)`;!isNaN(X)?I=X:I=1;!isNaN(N)?`${B}edit${Q}1%20${parseInt(N)+I+S}`:`${B}add${Q+I+S}`))
!subtract
$(urlfetch $(eval B=`https://twitch.center/customapi/`;Q=`quote?token=PRIVATE_TOKEN&data=`;S=`&silent=1`;X=parseInt(decodeURIComponent(`$(querystring)`));N=`$(urlfetch https://twitch.center/customapi/quote/list?token=PUBLIC_TOKEN&no_id=1)`;!isNaN(X)?I=X:I=1;!isNaN(N)?`${B}edit${Q}1%20${parseInt(N)-I+S}`:`${B}add${Q}-${I+S}`))
!counter
\*Insert Start of Message Here\* $(urlfetch https://twitch.center/customapi/quote/list?token=PUBLIC_TOKEN&no_id=1) \*Insert End of Message Here\*