Ultraman Trigger: NEW GENERATION TIGA hasn't aired yet. But the spin-offs have been already announced. The first spin-off is "Marlu-Dex" (Japanese Title - MaruttoNavi) which will feature Marluru guiding you through the information, background, and mythology on the Ultra Heros, Kaiju, and mysterious celestial items appearing in Ultraman Trigger.
The second spin-off is titled Secret Origins of the Nursedessei: The Struggle of Special Section 3 (English Title is yet to be confirmed by Tsuburaya Productions). In this, we will follow Marlulu's story before she enlisted in GUTS-Select, during her time at the TPU’s Department of Technological Development: Special Section 3. It will also follow the story of Nursedessei's origin.
Two new characters will appear in this spin-off. They are Masmichi Hotta (Munetoshi Takubo), Terumi Yazaki (Shio Yamazaki).
Both the shows will be streamed on Tsuburaya Productions' streaming platform - TSUBURAYA IMAGINATION. The users are required to have either standard or premium subscriptions to watch these.