Authorize.net The integration can be enabled by these simple steps:

Enter the required API keys with Authorize.net on Payments ➝ Integrations. There are 3 keys that are required to be entered for connecting to Authorize.net:

• Login Id

• Transaction key

• Signature key

How to obtain Login Id and transaction key can be found

Here

Test cards for Authorize.net integration:

Expiration can be any future date and any 3/4 digit CVC: 

4007000000027 (Visa)

4012888818888 (Visa)

4111111111111111 (Visa)

370000000000002 (American Express)

5424000000000015 (Mastercard)

2223000010309703 (Mastercard)

2223000010309711 (Mastercard)

6011000000000012 (Discover)

3088000000000017 (JCB)

38000000000006 (Diners Club/ Carte Blanche)

Note: You are not required to disconnect Stripe for connecting to Authorize.net. You can connect to both gateways on the integrations page. However, since you have connected two different gateways for processing payments, you will need to define a default gateway for processing order form payments