How is it free?
If anyone wants to use ChatGPT4 for free (apart from Bing) try https://chat.forefront.ai/.
It also has bots with personas and ability to generate images using #imagine
Discussion
I had to ask Yoda 
But I think this is their pricing tiers https://forefront.ai/pricing
They probably have a free tier with some limitations (haven’t figure it out yet) and scales up with paid tiers.