And don't forget to check if you have the zstd library itself installed
dpkg-query --list "*zstd*" | grep "ii"
libzstd-dev:amd64 1.5.4+dfsg2-5 amd64 fast lossless compression algorithm -- development files
libzstd1:amd64 1.5.4+dfsg2-5 amd64 fast lossless compression algorithm
php-zstd 0.13.1-1+0~20231125.8+debian12~1.gbp48ebd9 amd64 Zstandard extension for PHP
php8.2-zstd 0.13.1-1+0~20231125.8+debian12~1.gbp48ebd9 amd64 Zstandard extension for PHP
php8.3-zstd 0.13.1-1+0~20231125.8+debian12~1.gbp48ebd9 amd64 Zstandard extension for PHP
zstd 1.5.4+dfsg2-5 amd64 fast lossless compression algorithm -- CLI tool