I rendered a HDRi on Blender from my ambient - to look like real state presentation - and I want to convert this HDRi file into a format acceptable on Facebook and / or other media as they doesn't open HDRi's. I don't even know what is the format of 360 (equirectangular, spherical actually) photos generated from cameras and phones, otherwise I could do my research on it :( Any help is appreciated! Thanks!!
Sorry for the links only answer, but this is too long for comments.
You are mixing two different concepts:
stands for High Dynamic Range image, that has larger colour values than those that can be displayed by any screen. They are used mostly as environment textures to light scenes.
2. 360 images
concept of environment projection https://wiki.panotools.org/Projections
Most HDRi is mapped used in 3D and VR is using equirectangular projection, but is not mandatory.
As to how to do this in blender, it has been asked before: