What is the problem?
What did you already try to solve it?
Have you tried running in safe mode and if so did it solve the issue?
serial.log or output on terminal tab at a minimum, browser error console if UI issue ... no logs, no support! Not log excerpts, complete logs.)
Additional information about your setup
OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ... as much data as possible
Successfully installed pip-20.2.4
(venv) pi@raspberrypi:~/OctoPrint $ pip install octoprint
DEPRECATION: Python 3.5 reached the end of its life on September 13th, 2020. P lease upgrade your Python as Python 3.5 is no longer maintained. pip 21.0 will drop support for Python 3.5 in January 2021. pip 21.0 will remove support for this functionality.
Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple
ERROR: Could not find a version that satisfies the requirement octoprint (from versions: none)
ERROR: No matching distribution found for octoprint