How to have full Ubuntu on USB disk

I am new to use Linux, so sorry for this stupid question.
I’ve try to have Full Ubuntu on my USB(it is 64GB), I’ve did it by this tutorial: , but when it writes it is complete to restart PC and remove my USB with installation medium(I’ve got another USB stick, 4GB which I used with rufus to boot Ubuntu), so now I my PC I’ve got plugged only the 64GB with installed Ubuntu, but when I open Boot menu, only Windows boot option will show there.
I will be very grateful for all the answers and have a nice day.

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Author Of this post: Tonda
Title Of post: How to have full Ubuntu on USB disk
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