How to make use of it:

1. Load the stylesheet show-password-toggle.min.css and JavaScript show-password-toggle.min.js into your Bootstrap challenge.

<link rel="stylesheet" href="./css/show-password-toggle.css" />
<script src="./js/show-password-toggle.min.js"></script>

2. Create a password visibility toggle button next to the password subject.

<input type="password" id="password" name="current-password" autocomplete="current-password" class="form-control rounded-right" spellcheck="false" autocorrect="off" autocapitalize="off" required>
<button id="toggle-password" type="button" class="d-none" aria-label="Show password as plain text. Warning: this will display your password on the screen.">
</button>

3. Replace the default toggle icon.

.input-password[type="password"]:valid {
  background-image: url("data:image/svg+xml,%3Csvg width='1em' height='1em' viewBox='0 0 16 16' fill='currentColor' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M13.359 11.238C15.06 9.72 16 8 16 8s-3-5.5-8-5.5a7.028 7.028 0 0 0-2.79.588l.77.771A5.944 5.944 0 0 1 8 3.5c2.12 0 3.879 1.168 5.168 2.457A13.134 13.134 0 0 1 14.828 8c-.058.087-.122.183-.195.288-.335.48-.83 1.12-1.465 1.755-.165.165-.337.328-.517.486l.708.709z'/%3E%3Cpath d='M11.297 9.176a3.5 3.5 0 0 0-4.474-4.474l.823.823a2.5 2.5 0 0 1 2.829 2.829l.822.822zm-2.943 1.299l.822.822a3.5 3.5 0 0 1-4.474-4.474l.823.823a2.5 2.5 0 0 0 2.829 2.829z'/%3E%3Cpath d='M3.35 5.47c-.18.16-.353.322-.518.487A13.134 13.134 0 0 0 1.172 8l.195.288c.335.48.83 1.12 1.465 1.755C4.121 11.332 5.881 12.5 8 12.5c.716 0 1.39-.133 2.02-.36l.77.772A7.029 7.029 0 0 1 8 13.5C3 13.5 0 8 0 8s.939-1.721 2.641-3.238l.708.709z'/%3E%3Cpath fill-rule='evenodd' d='M13.646 14.354l-12-12 .708-.708 12 12-.708.708z'/%3E%3C/svg%3E") !important;
}
.input-password[type="text"]:valid {
  background-image: url("data:image/svg+xml,%3Csvg width='1em' height='1em' viewBox='0 0 16 16' fill='currentColor' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath fill-rule='evenodd' d='M16 8s-3-5.5-8-5.5S0 8 0 8s3 5.5 8 5.5S16 8 16 8zM1.173 8a13.134 13.134 0 0 0 1.66 2.043C4.12 11.332 5.88 12.5 8 12.5c2.12 0 3.879-1.168 5.168-2.457A13.134 13.134 0 0 0 14.828 8a13.133 13.133 0 0 0-1.66-2.043C11.879 4.668 10.119 3.5 8 3.5c-2.12 0-3.879 1.168-5.168 2.457A13.133 13.133 0 0 0 1.172 8z'/%3E%3Cpath fill-rule='evenodd' d='M8 5.5a2.5 2.5 0 1 0 0 5 2.5 2.5 0 0 0 0-5zM4.5 8a3.5 3.5 0 1 1 7 0 3.5 3.5 0 0 1-7 0z'/%3E%3C/svg%3E") !important;
}

4. To disable the Password Visibility Toggler on Internet Explorer, simply load the script as a module.

<script src="./js/show-password-toggle.min.js" type="module"></script>

Vanilla JavaScript Password Visibility Toggler For Bootstrap, Show Password Toggle Plugin/Github, eye toggle icon in password field, toggle password visibility

See Demo And Download