I am using ubuntu 22.04, and protobuf is 3.6.1 which is quite old. so I tried to update the protobuf with the following commands.

PROTOC_VERSION=29.1

curl -LO https://github.com/protocolbuffers/protobuf/releases//download/v$PROTOC_VERSION/protoc-$PROTOC_VERSION-linux-x86_64.zip

unzip protoc-$PROTOC_VERSION-linux-x86_64.zip -d $HOME/.local

export PATH="$PATH:$HOME/.local/bin"

rm protoc-protoc-$PROTOC_VERSION-linux-x86_64.zip

In the path of $HOME/.local/bin,

./protoc --version
29.1 

but √

is still 3.6.1 

I have updated the protoc path, why not working ?