After flashing the phone with the SP Flash Tool, the message "NOT VERIFY" appeared on the main screen and it is not possible to use the SIM card. SIM card working. Can you restore everything?
When you completely reformat and flash a MTK device, you probably will get two problems at the same time.
First problem is the Not Verify mark, this is only a cosmetic problem which will be hopefully be solved soon here.
Second problem are missing or wrong IMEIs.
When I began to be active in smartphone forums, my phone made strange problems. I found out that I had published my real IMEI (in a picture or file), somebody abused it with a stolen phone, and I was punished for helping. Since then, I know why images or pictures contains wrong or missing IMEIs
The solution is simple: Download the latest version of SN write tool https://snwritetool.com/category/download
, look at the instructions on https://androidmtk.com/use-sn-write-tool
and write the correct IMEIs in your phone.
With the MT6739 chipset you will have problems to choose the correct MD1_DB file, but when you activate the options "Load AP DB from DUT" and "Load Modem DB from DUT" you will be successful.
Best regards from Switzerland