Use external power supply as UPS

You asked if a portable power station can be used in place of a UPS. Well, the answer depends on the capabilities of the power station you're planning to use. Like I said above, many portable power stations don't have the Battery Bypass feature that's essential for using a power station in place of a UPS.

An Uninterruptible Power Supply (UPS) is a device that provides emergency power to your electronic devices and equipment when the main power source fails or fluctuates. A UPS can help prevent data loss, equipment damage, and downtime caused by unexpected power interruptions.

When plugged into an electrical outlet, a UPS uses a function called Battery Bypass to feed power directly from the outlet to the computer (or whatever device is plugged into it). In other words, the power coming in from the grid bypasses the battery completely to directly power the load device (s).

The purpose of a UPS device isn't to keep gear running for extended periods of time. They are actually designed to serve as an always-ready short-term backup power source that keeps your computer gear powered up long enough for you to save any open files and perform a normal (i.e. safe) shutdown procedure when the power goes out.

For critical devices such as medical devices or IT infrastructure, EcoFlow power stations can NOT be used as an uninterrupted power supply (UPS) unit. This is because it is not meant to be in constant use (as UPS units need to be) and power stations cannot switch from grid-supplied power to internal-battery power instantly like a UPS system.

Finally, it's important to note that using a Jackery power station as a UPS will require some manual intervention. Unlike a dedicated UPS system that will automatically switch to battery power in the event of a power outage, you will need to manually connect your devices to the Jackery power station to ensure that they receive backup power.