Searching for past flight data

Hello.

Im searching for departure time, landing time, registration and flight number of my two flights six years back. I was quite little then, but now i'm trying complete my flight log. I have a flightradar Gold sub, but the flight history goes only 1 year back.

It may be somewhat tricky to search for these flights, because the airline is a little charter airline with many subsidiaries, but im fairly sure the airline code and aircraft type are correct. The details i know are:

8th January 2020, HEL/EFHK - LPA/GCLP, departure in the morning and arrival in the afternoon, Jettime (JTD/JO), B737-800, most likely of danish registration (OY-???)

15th January 2020, LPA/GCLP - HEL/EFHK, departure in the afternoon and arrival late evening/early night, Jettime (JTD/JO), B737-800, most likely of danish registration (OY-???)

I already tried flightera.net, but it didn't seem to find it.

I apologize for my poor english, i'm not a native speaker.

If someone has the goodwill to help, i thank very much in advance.