You're looking at StableBuild's Deleted PyPI mirror - where we index all deleted packages from the Python package registry.

rllte-core
0.0.1b3

This version was deleted from PyPI around 2023-10-04. Installing fails with:
$ pip3 install rllte-core==0.0.1b3 ERROR: Could not find a version that satisfies the requirement rllte-core==0.0.1b3
View other deleted versions of rllte-core

Install through StableBuild

You can install this package from StableBuild's PyPI snapshots from before the version was deleted:
pip3 install \ -i https://YOUR_API_KEY.pypimirror.stablebuild.com/2023-10-03/ \ rllte-core==0.0.1b3
Sign up for StableBuild to get an API key (it's free and takes <60 seconds!)

Or, download files manually

And install manually via pip:
rllte_core-0.0.1b3-py3-none-any.whl (218.6KB)
rllte_core-0.0.1b3.tar.gz (8.2MB)