The user should see a print result of their current field map

My problem is when I execute the program and insert the instructions I don’t see that print the new value in array 2d.

print() {
        // I can prin the array, thanks design6726512087 he is in the forum of codecademy
        console.clear();
        this._fields.forEach(rows => {
            console.log(rows.join(''));
        });
    }
playGame() {
        while (!this.gameOver) {      
            this.print();      
            const promptInputUser = prompt("Instructions to move is: {u as up}, {d as down}, {l as left} & {r as right}.nWich is your path? ");
            // Call the function to move into array 
            this.instructionsToMove(promptInputUser);
        }
        console.log("Game Over");
    }

When I call the function in playGame() to print the instruction in array but throw a problem: TypeError: Cannot read properties of undefined (reading ‘forEach’).
Also I hope you can understand my english is not the better but I trying to write.