subscribe button - Robuta Search

https://www.socialmediatoday.com/news/twitters-adding-a-new-subscribe-button-to-newsletter-creator-profiles/601640/

Twitter is testing a new newsletter 'Subscribe' button on profiles.

https://pngimg.com/image/93378

Subscribe button PNG PNG image with transparent background, size: 1081x354px. Subscribe button PNG in high resolution. Download:...

https://wordpress.org/support/plugin/subscribe-youtube-button/reviews/?filter=1

https://userstyles.org/styles/254284/youtube-red-subscribe-button

Style Youtube with the custom theme Youtube - Red Subscribe Button by sapondanaisriwan. Check out more themes and styles at Userstyles.org

https://wordpress.org/support/plugin/native-youtube-subscribe-button-with-subscriber-counter/

https://greasyfork.org/en/scripts/531990-youtube-subscribe-button-themes?locale_override=1

Custom animated subscribe button themes