Hi Dmytro,
Welcome to Adobe Community !!
To generate Smart Crop for Video asset :
1)You need to have Dynamic Media configured on your AEM Author Instance or AEM as a Cloud Author Environment.
2)You need a copy the OOTB Video Profile (Tools -> Assets -> Video Profiles) and create a copy if it.
3) Now enable "Smart Crop" and add Crop ratios and save the changes.
4) Apply that Video profile on a folder and then upload your video asset to make sure video is processed and Crop ratios are created.
A small demo about applying Smart Crop for Video is shows here : https://experienceleague.adobe.com/docs/experience-manager-learn/assets/dynamic-media/dynamic-media-smart-crop-video.html
Thanks,
Vikram Gaur