Your host is moving your site to a newer PHP version. Bumpcheck tells you which plugins and themes would stop working, before the switch.
Pick a PHP version from 8.0 to 8.6 and run the scan. Each plugin and theme gets one of three results:
Removed and deprecated functions, constants and INI settings. Array offsets with curly braces. The (unset) and (real) casts. Constructors named after their class. "${var}" in strings. Missing return types on ArrayAccess, Iterator, Countable and JsonSerializable methods. Serializable without __serialize(). Parameters that are nullable only through a null default. Required parameters after optional ones. get_class() without an argument. A third argument to define(). Deprecated mb_convert_encoding() encodings.
The scan reads code and does not run it. Problems that depend on values at run time are out of reach, for example passing null to a function that needs a string, or properties created on the fly (deprecated in PHP 8.2). A clean result means nothing known was found. Test on a staging copy before you switch a busy site.
A separate add-on adds a weekly or daily scan with the result by email, CSV and JSON export, and a WP-CLI command. Details and price: getbumpcheck.com.