: Uploading an avatar requires the VRChat Creator Companion and Unity. Once your project is built, you use the "Build & Publish" option in the SDK to make it live. Create a New Avatar If you need to make one first, these free tools can help: Creating Your First Avatar | VRChat Creation

: You can upload custom 3D models to the Roblox Creator Hub to sell them as items or use them as your personal character.

To "post" an avatar generally means to set a profile picture or share a digital character on social media or gaming platforms. Here is how you can do it across major platforms: Social Media