Hi,
This is a known issue in JetPack 4.3:
Please reset your pip3 tool to version 20.2.4 and try the installation again.
$ sudo pip3 install -U pip==20.2.4
$ sudo pip3 install --pre --extra-index-url https://developer.download.nvidia.com/compute/redist/jp/v43 tensorflow==1.15.2+nv20.3
Thanks.