How can I add a custom logo to Frontegg emails?

You can add your custom company logo by editing the HTML:

Frontegg Portal ➜ [YOUR_ENV] ➜ Emails ➜ email template

Careful! In order to prevent emails from going to spam,
Make sure to test the new HTML template after applying changes.
You can always revert the changes by clicking on "Reset to default" at the bottom of the page

For example, here we add an <img> tag ➜

<p style="text-align:center;"><img src="https://i.imgur.com/MMrsTyc.jpeg" alt="cute_dog_logo" width="200" height="200"/></p>

(We wrapped inside a <p> tag to align to center)

To the HTML of the "Reset Password" template ➜

Here is the final result ➜

NOTE: 

It isn't recommended to use .svg files as Gmail might not be supporting that format. Please refer to this related discussion.