Find the right Trainingsplan/Workout as Mountainbiker

Hello at all!

in summer times I only ride my Enduro mtb in the alps. most of the time i have to do the climbs on my own. in the winter i dont have to possible to go riding outside because of the lot snow. so that´s why I started zwifting last winter season. back then i did the 6wk beginner ftp builder. it was great, i´ve felt the results immediately when I was on my first ride with my MTB. So, now I am looking for the best Trainingsplan / Workout for the next month since winter is knocking on my door. Do you have any recommendations for me which plan to use? I ´ve got a time window of about 90 minutes per day. And I like to improve my uphill performance. that means being faster without being exhausted. My uphills are most of the time about +/- 1500 metres at once.