I created attribute sets for mice, inserting DPI, Macro etc.
When I create a new product, I do not leave any custom fields after I select the Attribute Set drop-down.
I'll post the photos.
Try following these steps:
1. Create customer_form.xml file in this location:
YourNamespace/YourModule/view/base/ui_component/customer_form.xml
2. Add these lines:
<?xml version="1.0" encoding="UTF-8"?>
<form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
    <fieldset name="customer">
        <field name="{{YOUR_ATTRIBUTE_CODE}}" formElement="input">
            <settings>
                <visible>true</visible>
            </settings>
        </field>
    </fieldset>
</form>3. Finally, run this command:
php -f bin/magento setup:upgrade
sorry but I do not understand where I have to place the file