https://mailchimp.com/features/custom-forms/
Use Mailchimp’s business sign up forms to turn website visitors into subscribers. Forms are customizable and include popup and embedded options.
businesssignformsfreepopup
https://docs.everestforms.net/docs/popup-forms/
If you need to show the Everest Forms as a popup, all you need to do is add a few attributes to the already existing form's shortcode.
popup formseverest
https://docs.everestforms.net/docs/have-trouble-with-integrating-file-upload-in-elementor-popup/
You may see the Elementor popup closing automatically when you upload a file in the Everest Forms plugin. You can troubleshoot this with the following steps.
file uploadtroubleintegratingelementorpopup
https://www.competethemes.com/blog/popup-form-wordpress/
May 9, 2021 - Design a beautiful popup form and add it to any page on your WordPress site. This tutorial works with all the top email marketing services.
popup formsaddbeautifulwordpresscompete
https://mailchimp.com/resources/how-to-design-sign-up-forms-that-work/
Mailchimp’s tips on signup forms, popup forms, slide-ins, and email opt-ins. How to welcome your site visitors with beautiful modals and grow your list.
popup formsworkexamplestemplatesmailchimp