There are a few free, popular online attachment style quizzes available online.
Most popular tests (they offer a quick and in-depth option)
This test is referred to in a lot of attachment books.
http://www.web-research-design.net/cgi-bin/crq/crq.pl
Diane Poole Heller Attachment Quiz
This quiz offers a useful pie chart at the end
https://dianepooleheller.com/attachment-test/
Personal Development School (Thais Gibson)
https://attachment.personaldevelopmentschool.com/
There’s also this slightly different test:
https://personality-quizzes.com/attachment-style/
They also offer a corporate quiz to see how your style affects your work relationships
https://attachment.personaldevelopmentschool.com/corporate-quiz
IDR Labs
Available in several languages. Results show secondary attachment style.
https://www.idrlabs.com/attachment-style/test.php
Official “Attached” Quiz
https://www.attachedthebook.com/wordpress/compatibility-quiz/?step=1