CHARCTER NOT DASHING LEFT.,MY 2D PLAYER DOES NOT DASH TO THE LEFT.

Here is the code, I can only dash right.

private IEnumerator Dash()
    {
        canDash = false;
        isDashing = true;
        float originalGravity = _rigidbody.gravityScale;
        _rigidbody.gravityScale = 0f;
        _rigidbody.velocity = new Vector2(transform.localScale.x * dashingPower, 0f);
        tr.emitting = true;
        yield return new WaitForSeconds(dashingTime);
        tr.emitting = false;
        _rigidbody.gravityScale = originalGravity;
        isDashing = false;
        yield return new WaitForSeconds(dashingCooldown);
        canDash = true;
    }

Hey, welcome to the forum,

first up, please use the code formatting button which you can find over the text input (the button with 1010101) next time to paste your code - I corrected your post for you. Also we are not on youtube, clickbait CAPSLOCK titles are not needed.

To get to the issue itself:
Assuming that your local scale does not change (as you did not state otherwise) you will ofc always dash in the same direction.

If you want to force that it has some direction i’d suggest you do something like this:

 private IEnumerator Dash(bool right)
 {
     canDash = false;
     isDashing = true;
     float originalGravity = _rigidbody.gravityScale;
     _rigidbody.gravityScale = 0f;
     if(right)
           _rigidbody.velocity = new Vector2(dashingPower, 0f);
     else
           _rigidbody.velocity = new Vector2(-dashingPower, 0f);
     tr.emitting = true;
     yield return new WaitForSeconds(dashingTime);
     tr.emitting = false;
     _rigidbody.gravityScale = originalGravity;
     isDashing = false;
     yield return new WaitForSeconds(dashingCooldown);
     canDash = true;
 }