To tokenize a Bank Account and the associated Routing Number (ABA Number) on Payrix:

POST /tokens

{
    "status":"ready",
    "customer": {
		"first": "Katharine",
		"last": "Token",
		"merchant":"t1_mer_5f860da6b6543a7409f7d76"
		},
        "payment":{
            "method": "8",
		    "number": "3829803325",
		    "routing": "021000021"
        }
}
CODE

Tokenizing a Bank Account can also be included in the Transaction Request:

POST /txns

{
    "merchant":"t1_mer_5ed00af8b04342424455582",
    "type":"7",
    "origin":"2",
    "token":{
        "customer": {
		    "first": "First",
		    "last": "Token",
		    "merchant":"t1_mer_5ed00af8b04342424455582"
		},
        "payment":{
            "method": "8",
		    "number": "3829803325",
		    "routing": "021000021"
        }
    },
    "total":"1000"
}
CODE

In both cases, look for the token in the response.data.id in the format to store as needed:

"id": "t1_tok_5f8641a89f25ad11bc81123