nushell: Sending keys on tmux does not work as expected

Question

I have this custom bash scripts to create tmux sessions and they always work with bash or fish but not with nushell.

#!/usr/bin/env sh

SESSION_TYPE=$1

if [ -z "$SESSION_TYPE" ]; then
	echo "No session type provided"
	exit 1
fi

WORK_PATH="$HOME/clones/$SESSION_TYPE"
# Selecting a repository to work on
SELECTED_REPO=$(ls "$WORK_PATH" | fzy)
REPO=$(echo $SELECTED_REPO | sed 's/\//-/g' | sed 's/\./-dot-/g')
SESSION="$SESSION_TYPE-$REPO"
REPO_NAME="$WORK_PATH/$SELECTED_REPO/"
# Generating the session name using the repository
SHELL=nu
EDITOR=nvim
# CUSTOM_COMMAND=""

if ! tmux has-session -t "$SESSION" 2>/dev/null; then
	echo "Creating new session..."
	tmux new-session -d -s "$SESSION"
	tmux new-window -n $EDITOR
	tmux send-keys "$SHELL" C-m
	tmux send-keys "cd $REPO_NAME" C-m
	# tmux send-keys "$CUSTOM_COMMAND" C-m
	tmux send-keys "$EDITOR" C-m
	tmux send-keys C-l
	tmux split-window -v
	tmux select-pane -t 1
	tmux send-keys "$SHELL" C-m
	tmux send-keys "cd $REPO_NAME" C-m
	# tmux send-keys "$CUSTOM_COMMAND" C-m
	tmux send-keys C-l
	tmux resize-pane -D 80
else
	echo "Session already exists"
fi

tmux -2 attach-session -t "$SESSION"

The C-m key are not send and when opening the session I get the following:

It shoul cd to the dir and open nvim, but it just gets the two lines together.

Do you know why this happens? The scripts runs inside bash so it is strange. Should I create a nushell equivalent script?