OpenSSL@1.1 not getting linked with Homebrew - trying to install postgresql

My system is OS Mojave 10.14.6, I got homebrew from this command :

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

when I try to install postgresql with the command
brew install postgresql

I have this error:

Error: An exception occurred within a child process:
RuntimeError: /usr/local/opt/openssl(at)1(dot)1 not present or broken
Please reinstall openssl(at)1(dot)1(dot) Sorry :(

When I try to install openssl(at)1(dot)1 I have this message:

brew install openssl(at)1(dot)1
Running `brew update --preinstall`...
==> Auto-updated Homebrew!
Updated 1 tap (homebrew/cask).
==> Updated Casks
Updated 8 casks.

Warning: openssl(at)1(dot)1 1.1.1n is already installed, it's just not linked.
To link this version, run:
brew link openssl(at)1(dot)1
➜ / brew link openssl(at)1(dot)1
Warning: Refusing to link macOS provided/shadowed software: openssl(at)1(dot)1
If you need to have openssl(at)1(dot)1 first in your PATH, run:
echo 'export PATH="/usr/local/opt/openssl(at)1(dot)1/bin:$PATH"' >> ~/.zshrc

For compilers to find openssl(at)1(dot)1 you may need to set:
export LDFLAGS="-L/usr/local/opt/openssl(at)1(dot)1/lib"
export CPPFLAGS="-I/usr/local/opt/openssl(at)1(dot)1/include"

For pkg-config to find openssl(at)1(dot)1 you may need to set:
export PKG_CONFIG_PATH="/usr/local/opt/openssl(at)1(dot)1/lib/pkgconfig"

And then when I try to force hombrew link openssl, I get this message

Warning: Refusing to link macOS provided/shadowed software: openssl(at)1(dot)1
If you need to have openssl(at)1(dot)1 first in your PATH, run:
echo 'export PATH="/usr/local/opt/openssl(at)1(dot)1/bin:$PATH"' >> ~/.zshrc

For compilers to find openssl(at)1(dot)1 you may need to set:
export LDFLAGS="-L/usr/local/opt/openssl(at)1(dot)1/lib"
export CPPFLAGS="-I/usr/local/opt/openssl(at)1(dot)1/include"

For pkg-config to find openssl(at)1(dot)1 you may need to set:
export PKG_CONFIG_PATH="/usr/local/opt/openssl(at)1(dot)1/lib/pkgconfig"

I added the lines to .zshrc file as suggested:

export PATH="/usr/local/opt/openssl(at)1(dot)1/bin:$PATH"
export LDFLAGS="-L/usr/local/opt/openssl(at)1(dot)1/lib"
export CPPFLAGS="-I/usr/local/opt/openssl(at)1(dot)1/include"
export PKG_CONFIG_PATH="/usr/local/opt/openssl(at)1(dot)1/lib/pkgconfig"

But I kept on having the message when retrying to intall postgresql

Error: An exception occurred within a child process:
RuntimeError: /usr/local/opt/openssl(at)1(dot)1 not present or broken

I also tried this command:

brew reinstall openssl

openssl(at)3 is installed and I get this message:

openssl(at)3 is keg-only, which means it was not symlinked into /usr/local,
because macOS provides LibreSSL.
and then when I try to

brew install postgresql

I have the same error:
Error: An exception occurred within a child process:
RuntimeError: /usr/local/opt/openssl(at)1(dot)1 not present or broken
Please reinstall openssl(at)1(dot)1(dot)

and The pg version in my rails gemfile is
gem "pg", "1.3.5"
but I just tried brew install pg,
and bundle install fails also.
If anyone could help, I am totally stuck here, thanks!
Cécile