Would it make sense to do a check for Safari before enabling Apple Pay? If you're using Chrome, you get this console error:

square.js:3 Initializing Apple Pay failed PaymentMethodUnsupportedError: Method unsupported: Apple Pay is only available on Safari.
at new Wf (square.js:3:375247)
at Yf (square.js:3:383212)
at square.js:3:386948
at Generator.next (<anonymous>)
at Jf (square.js:3:383366)
at a (square.js:3:383570)