My recomendation is to make videos on youtube, showing the process creation, and then go to the social networks, facebook for example, and post your progress on there, use the hashtags to get more views, and also be creative for campaign events, for example, there was this nintendo direct that showed AAA games, and you know what other indie devs did??? they got views in their social networks by making a post with a video fo their games and telling that if silksong is announced or showed in the direct they will give away a key for their game, those posts got pretty much attention and they also got their game to be known by the gamers. So be creative... And maybe it is a little to late on the developing but you have to promote your game since the very start of developing...