hstr options to maintain history per tmux panel when used with Oh My Zsh

[faxotherapy]

Hi,
I use tmux with Oh My Zsh and have activated history per panel; each panel has its own command history. Unfortunately, hstr does not seem to take account of that config.

Related entries in my .zshrc file contains:

# Disable shared history
unsetopt share_history

# HSTR
export HSTR_CONFIG=hicolor 
export HISTFILE=~/.zsh_history

What should I use for export HISTFILE then?

Thank you.