You can import your custom inventory in XML/CSV file format using the WP All Import solution.
Sample import files in XML/CSV file format are provided that you can check the compatibility of the file structure with your importing files.
Find the All Import menu from the Dashboard to upload your custom XML/CSV files, select Listings as the location of the data file, and click Continue to Step 2.
Also, You can use uploaded XML/CSV files in WordPress as well as direct links via Download a file and Use existing file buttons.
In this step, you can Add Filtering Options in order to sort the needed listings or go to the next step.
Drag the variables from the right column to the field where you want to import them.
Put your images only to the STM Listing Add-On section. Make sure that the name of the images are unique, even if they are located in different directories.
After making sure that all fields are filled in, proceed to the next step, click the Auto-detect button and continue the process.
Now your listings are ready to import.
All of your imported templates will get the Default Listing Template after the import process completes. Make sure that you set the default template for a single listing before starting the import process.