Turns out that the Development branch of MultiMC already has a feature to import a FTB App modpack. This app is discontinued.
Downloads and exports FTB modpacks to MultiMC
The aim of this application is not to remove the ad revenue of the FTB team. If in any point of future the FTB app adds a option to export a modpack to MultiMC (or vice versa), this application will be discontinued. PLEASE, support the FTB team by downloading and using the official FTB app.
Ads or any form of monetization is not present. I'm not trying to take money from the FTB team or modders, I'm just creating a tool that I needed for myself.