View Source ExTDLib.Method.SetStickerMaskPosition (ExTDLib v0.0.4)

Changes the mask position of a mask sticker; for bots only. The sticker must belong to a mask sticker set created by the bot. Returns object_ptr<Ok>.

NameTypeDescription
stickerInputFileSticker.
mask_positionmaskPositionPosition where the mask is placed; pass null to remove mask position.

More details on telegram's documentation.