No. You have to have the SIM, activate it and buy a membership before February 1st to get the €7.99 per month offer..
Unless they extend the offer again before then.
"This 100GB membership is only available to new 48 customers who activate their 48 SIM (by inputting activation code found on your sim packaging via the link activate and purchase a 100GB membership between the 8th September 2020 and the 1st February 2021 (Offer Period). "
Hope this helps.