Very confused about MPV HDR, is it really HDR?

Hello friends. I am new to HDR and I have a Hisense HDR TV.

I have connected Windows to the TV and I play HDR movies in mpv with these commands in mpv.conf:

gpu-api=vulkan

tone-mapping=spline

gamut-mapping-mode=perceptual

In the Nvidia panel I have 10-bit and YCbCr422 set.

I like the way the movies look, but the TV doesn't show that the content is actually HDR and I don't know if I'm seeing real HDR or not.

On the Amazon Fire TV stick, when playing a movie, the TV shows settings for HDR, HDR10 and Dolby Vision, but on Windows with mpv as I explained, it shows the normal or SDR content setting.

I am very confused and I don't know if I'm actually seeing real HDR or not. The colors are very well represented.

When playing HDR content I don't notice anything.

EDIT: With MPC-HC and MadVR in HDR tone map I also don't see the TV switching from normal mode to HDR mode. Am I not seeing real HDR either?