MultiPortDownloadTool is a another tool from MediaTek used in flashing basic or feature phones. MultiPortDownloadTool can only flash mtk basic or feature phones with firmware containing .cfg file. It should not be confused with MTK SP Multi Port Download Tool.
To flash this basic phones, follow the tutorial below
Click OK on the dialogue box that pops up with Fail
Click File and select Open Download Agent File
Now Click Image Folder button
Navigate and select the folder containing the ROM.
Click OK on the window that appears with Load Files Success
Now on Multi Download Tool, tick COM Port number, USB & Select Download ROM and Format
Click Start button on the line with the COM Port number that the phone was connected to.
The process starts with a red bar followed by purple then yellow.
When you see DL OK with 100% yellow bar, the process is complete
You can now disconnect and reboot Phone
If you have null/invalid imei after flashing your device, click here
Follow the screenshot below for the complete process