To import STEP files from JLC to Altium, you can follow the steps below. Additional documentation and information beyond what is covered in the document is available here:
https://pypi.org/project/JLC2KiCadLib/
Using Python, install the package using pip install JLC2KiCadLib.
Ensure you navigate to the folder where you want the STEP files to save using cd before moving on to the next step.
To download the part, run the command JLC2KiCadLib {partnumber} .
You can find the part number in the JLCPCB Part # row on the product page.
For example, for the AXP2101 PMIC:
The command to install the STEP files for this product would be JLC2KiCadLib C3036461 .
Navigate to \footprint\packages3d inside the downloaded folder. The folder will be placed wherever your command line directory is.
You can import this file into your Altium footprint. Ensure to change height and positioning to line up the model as best as possible.
Note: WIP Guide (feel free to add anything i missed)