Action Details
Requirements and how-to articles for Twitter's action:

paid action
Promoted Video tweets allow your video to be seen by a wider audience.

You need this to get it done:

The title which appears under the video (maximum of 70 characters.)
File format: .mp4/.mov
Aspect ratio: 16:9 or 1:1
Maximum file size: 1GB
Maximum video length: 2 minutes and 20 seconds (however some advertisers are eligible to request an increase of up to 10 minutes)
Video codec: h.264 (High Profile)
Audio codec: AAC-LC
Frame rate: 30fps (frames per second)
Minimum bitrate: 5,000Kbps
Tweet Text
Text to accompany the video (maximum of 280 characters.)
The description which appears under the video (maximum of 200 characters.)
File format: .jpg/.png
Maximum file size: 5MB
Recommended aspect ratio: 16:9 or 1:1
Minimum image resolution: 640 x 360 pixels.
Requirements missing or found errors? Report

How-To Articles
A list of useful links for you:

Twitter Business - Advertiser creative specifications
Official information on creative specs for ads.
Link missing here or found errors? Improve How-Tos