Release testing instructions for WC Payments 3.9.0

Add IPP print receipt preview to Card Readers page

Expected outcome

There is a Preview a printed receipt link under the Receipt Details tab of the Card Readers page of the Payments menu. By clicking this link, a merchant can see a preview of a printed receipt.

Testing instructions

1. Enable Card Readers in admin menu by following instructions in this PR
2. Go to Payments -> Card Readers -> Receipt details
3. Modify any of available settings. Note that logo is not available to be previewed yet.
4. Click on Preview a printed receipt link
5. Observe that the generated receipt contains the modified settings data
6. Reload the page
7. Observe that the generated receipt contains the original unmodified data

Do not show the multiple currencies inbox note if the merchant doesn't have an account set up yet.

Expected outcome

There is no inbox note related to the setup of multi currency if there is no connected account yet. Once a connected account is created, then there is a multi currency inbox note.

Testing instructions

1. Create a fresh JN site with WooCommerce and WCPay Dev Tools plugins
2. Install the WooCommerce Payments plugin
3. Acknowledge that there is NOT a multi currency note in the inbox
4. Set up your WCPay account
5. Acknowledge that there is now a multi currency note in the inbox