No plug-ins required. Motion included.
Just type in your text, and the box will automatically adjust to fit!
You can also freely customize the font, color, and background On/Off.
8 seconds.
Available in After Effects 2025 (ver. 25) and later.
This is the Japanese version.
English version is here
https://www.motionelements.com/after-effects-template-55179506-gradient-box-title-english