On April 24th, 2020, it was announced that Pokémon Detective Pikachu would make its terrestrial television debut on May 22nd, 2020 as an uncut broadcast from 9PM to 10:59 PM JST. The official Japanese Detective Pikachu Twitter account posted the announcement and linked to NTV's website which had an article about the movie.

The Hollywood Electrocuting blockbuster is coming back!
Detective Pikachu makes its terrestrial debut on Friday, May 22.
Don't tell me you've forgotten that wrinkled face of Pikachu
Let's all enjoy it at home!

あの"ハリウッド感電超大作"が帰って来るーーー！
5月22日（金）金曜ロードSHOW！で「名探偵ピカチュウ」の地上波初放送が決定‼
忘れたとは言わせない、あのしわしわ顔のピカチュウ
を、お家でみんなで堪能しよう

The movie "Detective Pikachu" aired for the first time on May 22nd, 2020 at 9:00 p.m. on Nippon Television Network's "Friday Road SHOW!" To celebrate the broadcast, a campaign was held at the Pokémon Center Online and Pokémon Centers and Pokémon Stores to get the promo card, Detective Pikachu (099/S-P) from Friday, May 22nd, 2020, 10 a.m. until supplies last.

5月22日（金）金曜ロードSHOW！の「名探偵ピカチュウ」放送当日から、ポケモンセンターオンラインで「名探偵ピカチュウ」のポケモンカードがもらえるキャンペーンを開催！とぼとぼ歩いてくるしわしわ顔をやさしく受け止めて

Pokémon Center Online
① Purchase 5 or more expansion packs, including 1 pack or more of the Movie Special Pack "Detective Pikachu", to get 1 promo card "Detective Pikachu". (limited to one promo card per order)
② Purchase at least 1 box (20 packs) of the Movie Special Pack "Detective Pikachu" and get 4 "Detective Pikachu" promo cards. (Up to 4 promo cards per order)

Pokémon Centers and Stores Nationwide
Purchase 5 or more expansion packs including 1 pack or more of the Movie Special Pack "Detective Pikachu" to get 1 promo card "Detective Pikachu". (Up to 4 promo cards per order)

At the time of this campaign, the Pokémon Centers and Stores in Japan were closed due to COVID-19 but the Pokémon Center Online was still open for online orders. The official card game site noted that this campaign maybe canceled for in-store purchases.