But I need to convert from "it" to "lm", even if I just change the format there will be errors that there are no such files, even if I change the configuration file
Yes, this is what PM2IM does.
Open your asset for editing in Content Manager - right-click and choose open for editing.
Run PM2IM as administrator.
Navigate the file open box to where your content is located.
Click on the .pm file.
Click on Convert.
If there is more than one .pm file, repeat the process for the others. File open, and convert. You won't have to browse this time around.
When done, close the program.
In Content Manager, open the config.txt file for editing - right-click and choose Open... Edit configuration file text.
In the config.txt file:
Remove the line asset-filename and the file name on the right. Preserve any spacing.
Add in the mesh-table as shown in the sample. Using only the parts you need. I think for a commodity, you will only need the top part and you can remove the section for the shadow. Pay close attention to the curly brackets to ensure you have the correct number of pairs.
Once added, save the config.txt file.
Submit the asset in Content Manager - right-click on the asset and choose Submit.
If all goes well, you'll have only warnings. If there are any errors, check your work.