You can simply right click on your Template Select on the edit page, Inspect Element (on Chrome) then you can check the different options in the select like “page-template.php” as value and find your template file. 🙂
<select id="inspector-select-control-0" class="components-select-control__input">
<option value="">Default</option>
<option value="page-my-account.php">My Account</option>
</select>
It should look like this with your own templates.