No, you may not submit video embedded or linked within your application unless expressly instructed to do so by a funding opportunity announcement’s instructions. Instead, submit video following NIH procedures for post-submission materials.
As explained on the NIH Center for Scientific Review’s Submitting Videos page, you should state your intent to submit video as post-submission material in your application’s cover letter and include a still image from the video within your Research Strategy section. Following application assignment, obtain your authorized organizational representative’s concurrence and then send the video directly to the scientific review officer for your application’s review group.
Acceptable content for videos is limited to demonstrations of devices and experimental data with a temporal element, i.e., to show how something functions or occurs over time or to demonstrate movement or change.
If you submit multiple videos, the aggregate length must not exceed 2 minutes for a single-project application or 5 minutes for a multi-component application. The file size limit is 25 MB.