This code will help you recover lost streak.
first open this link : https://support.snapchat.com/en-US/i-need-help?start=5695496404336640
now enter the snap IDs in the code in place of blanks enter as many ids you want to recover streak with.
the change in code is shown in the above image.
After doing this changes run the code and enter the details asked in the prompt window. immediatly after entering the details open the webpage we have opened earlier. https://support.snapchat.com/en-US/i-need-help?start=5695496404336640