For me, I had php 5.4 installed, but an upgrade to php 7.3 worked for me.
brew install php@7.3
Then you'll likely need to add the new php version in your path. This basically means that when you load up your shell it knows where find the path to the files that you are using. For me, since I'm using zshrc that command is:
echo 'export PATH="/usr/local/opt/php@7.3/bin:$PATH"' >> ~/.zshrc
For you, if you have all your path and aliases in bash profile then the command would be this instead:
echo 'export PATH="/usr/local/opt/php@7.3/bin:$PATH"' >> ~/.bash_profile
Then, all you need to do is either source your zshrc or your bash_profile file, OR close that tab and open a new one. The source command basically says "hey, make sure you have an updated list of my aliases and path info". This naturally happens when you open a new shell, but you can force that with a command like:
source ~/.bash_profile
And then it worked for me. Good luck.