You haven't mentioned if you are using a framework of any kind for your styling and features.

If you are using Bootstrap CSS then you want to look at Modals.

https://getbootstrap.com/docs/5.1/components/modal/

Note: Don't forget to change the version to the version of Bootstrap you are using.

If you are not using Bootstrap CSS and instead another framework, check the related documentation for Modal behaviour and implement as instructed.

If you are not using any frameworks or the framework you are using doesn't support modal behaviour, then please check out the links below.

• https://webdesign.tutsplus.com/tutorials/how-to-build-flexible-modal-dialogs-with-html-css-and-javascript--cms-33500
• https://www.w3schools.com/howto/howto_css_modals.asp
• https://www.w3docs.com/snippets/javascript/how-to-create-a-modal-dialog-box-with-css-and-javascript.html
• https://www.youtube.com/watch?v=6ophW7Ask_0
• https://www.youtube.com/watch?v=XH5OW46yO8I

Once you have built your modal, you can then add a form to the modal's body.

Good Luck!