For those running their own LND node these fields can be obtained as follows.

Macaroon (HEX)
xxd -p -c2000 /$HOME/.lnd/data/chain/bitcoin/mainnet/invoices.macaroon

Certificate
xxd -p -c2000 /$HOME/.lnd/tls.cert

I verified this with Alby support.

For those running their own LND…