Wrong installaion cuda toolkit 11 on ubuntu 20

hi everybody,
I want to install tensorflow on my machine with cuda.
I have a gtx 10070 ti and ubuntu 20 lts , I follow the porcedure but during install failed and give some packets lost.
the system don’t install some packet and at last give me that the nvidia-cuda-dev : depends form libcublas10 (= 10.1.243-3) but the version 10.2.3.254-1will be installaed
reccomand: libnvcuvid1 but is not able to installed.
i’m blokect at this poiint and i can’t go on.
Can someone help me or give me a procedure to do.
thank a lot
regards.
Alessandro