PhpOffice\PhpSpreadsheet\Collection\CacheInterface not found

[gdanen]

I have installed PhPSpreadsheet using Composer and PhpOffice\PhpSpreadsheet\Collection\CacheInterface seems to be missing.
What to do?

TIA
Gerry

[gdanen]

I was trying to manually include dependencies, as I am not able to run composer on my shared host server.
It was suggested to install locally and then let composer bring in the files, after which the relevant files are uploaded to the server.

[MarkBaker]

It's not PhpOffice\PhpSpreadsheet\Collection\CacheInterface, it's Psr\SimpleCache\CacheInterface, which is included as part of the psr/simple-cache dependency. It should be in the vendor/psr/simple-cache/src/ folder. and made available within the autoloader when you include vendor/autoload.php.