You'll need to create a custom signup form to use this feature.
The Memberstack system requires a password to sign up and log in, but it doesn't know or care who sets the password. For an email-only login to work, we need to fake out Memberstack. Sshhh don't tell anyone. 😉
NOTICE: This workaround reduces the security of your site.
Instead of adding a visible and empty password field to your forms, you’ll need to add a hidden password field with a pre-set value. All of your members will have the same default password.
Here's some code to get you going:
<input type="hidden" id="pw" name="setPassword" value="TYPEaRANDOMpassword" data-ms-member="password">
This code should go inside your form between the email field and submit button. You may need to place it inside of a "Custom Embed" or "Custom Code" element depending on your site builder.
Note: To build on top of this, you can also write custom code to generate a password on the front-end to give each user a unique password that they can use to start. Here's a tutorial that one of our community members made to illustrate this.