Okay, you will need some additional equipment.
The tv model you have is just a standard tv, it is not a "smart' model tv.
At this time directv does not offer netflix through any of their devices. Dish network does, and some cable companies do, but directv boxes do not support netflix.
One option would be to buy a new tv that is a smart model and has apps built in.
The alternative is that for $30-100 you can buy a roku, roku4k, fire tv, htpc or smart bluray player and get all the same functions and many more, with better performance and lower cost.
Any of these devices would connect to the tv with a hdmi cable, link up to your home wifi network, and then give you access to netflix, hulu, amazon video, etc.
Of these I'd recommend the fire tv or roku device.
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