We don’t have built-in way to customize login form. However, You can override the login template by copying it to the yourtheme/user-registration/myaccount/form-login.php
-> Go to wp-content/plugins/user-registration/templates/myaccount/form-login.php
-> Copy this file.
-> Go to wp-content/themes/your-choosen-theme/ and create a folder user-registration and inside this folder create folder myaccount.
-> Paste the copied form-login.php file here and edit to your requirements. This file will override the plugin’s file.
Basically, the path to be: yourtheme/user-registration/myaccount/form-login.php
I would love to say that you’re right, but I don’t see it.
I have a couple of screen prints to show the folder structure and name, so that you can see that I’m using the correct names & structure (or not…)
You can find the screenprints here: https://1drv.ms/f/s!AiZg1q2e9vdxhByBKTd05uAOak1k
I have adapted the form-login.php significantly, just to check whether or not this file is used indeed.
Once I see that changes in it appear on the website, I will make the modifications the way I like them.