Hi and welcome to windows central forums
Windows 10 is unsupported for your lumia 1020 or for the x20 series of lumia. Microsoft has now blocked the use of insiders to download insider builds for these ineligible devices and hence you are not receiving them.
To experience windows 10 mobile you can buy a new device running windwos 10, like the Microsoft Lumia 950/xl its on a heavy discount at Microsoft stores .
If you need additional help or want to reply to this thread , please check the instructions on
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