As listed in the image above (click for full-size), there will be one free option to watch the video (BS11) and two pay options (dAnimeStore — Docomo’s anime offering & NicoNico).  Note that all three options are before the official DVD release on 4/27/2018.

Details

Televison

Station: BS11
Air Dates:  Part 1 — 3/21/2018  & Part 2 — 3/22/2018
Air Time:  27:00 ~ 27: 30
Note:  Only 2 of the 3 episodes from the DVD will air

Online

Site:  dAnimeStore (DOCOMO)
Episodes:  1, 2, 3
Price:   1,800 yen (excluding tax) for the set; individual episodes may not be purchased
Sale Dates: 3/23/2018 @ 12: 00 ~ 4/30/2018 @ 18: 00
Viewing Duration: 7 days
Note: You can watch the episodes as often as you’d like during that 7 day period

Site: NicoNico video
Episodes:  1, 2, 3
Price:   1,800 yen (excluding tax) for the set; individual episodes may not be purchased
Sale Dates: 3/23/2018 @ 12: 00 ~ 4/30/2018 @ 18: 00
Viewing Duration: 7 days
Note: You can watch the episodes as often as you’d like during that 7 day period

URL:  https://www.animatetimes.com/news/details.php?id=1520846022