To enable 4K upscaling on your Sony TV, follow these steps:
Go to the TV's home menu and select Setup.
Scroll down and select HDMI Settings.
Choose HDMI In 4K Scaling and select the setting you want.
Auto enables video scaling control of 4K HDMI output automatically if you connect a 4K-compatible TV.
Alternatively, you can also enable 4K upscaling through the TV's picture settings. Go to the picture settings menu, select Display, and then select Upscaling. From there, you can choose the upscaling mode that best suits your needs.
It's important to note that not all content will be upscaled to 4K, as it depends on the source material. However, enabling 4K upscaling will allow your TV to upscale lower-resolution content to near 4K quality, providing a better viewing experience.