It takes a long time to generate thumbnails for each video

After importing a video into Premiere Pro, it takes a long time to generate thumbnails for each video, and the video needs to be on the screen to generate thumbnails for the video I want to generate. This is very annoying for me. I have to work with thousands of video clips, and it takes five to ten minutes to generate the thumbnails for each clip. What's even more annoying is that every time I close the project, I have to generate those thumbnails again when I reopen the project. Is there any way to automatically generate thumbnails and not have to generate those thumbnails repeatedly, even after closing the project? If not, I would like to request Adobe to provide a solution for this.