Login to back-end of WordPress website, select Users, then Add New. You can skip this step if you are going to use existing Administrator or Shop Manager user.
Input your Username, Email, Password. Select “Shop Manager” or “Administrator” as Role. Then Click “Add New User”.
Make sure the Rest API is enabled.
Select “Keys/Apps”, and click “Add Key”.
Select the user you have just created or existing administrator, select Read/Write for Permissions, then click “Generate API Key”.
Please leave this screen on and Login to the system Setup.
Input your website URL and copy paste Consumer Key and Secret to the setting screen, then click “Test Connection”.
Input the user name and password you have just created or existing administrator user name and password.
Check rest of settings and click Save.