fluentforms_lost_password_snippet.php

add_action('fluentform_before_insert_submission', function ($insertData, $data, $form) {
   
 if($form->id != 17) { // 17 is your form id. Change the 17 with your own login for ID
        return;
    }
    $redirectUrl = home_url(); // You can change the redirect url after successful login

    if (get_current_user_id()) { // user already registered
        wp_send_json_success([
            'result' => [
                'redirectUrl' => $redirectUrl,
                'message' => 'Your are already logged in. Redirecting now...'
            ]
        ]);
    }

    $email = \FluentForm\Framework\Helpers\ArrayHelper::get($data, 'email'); // your form should have email field
   
    if(!$email) {
        wp_send_json_error([
            'errors' => ['Please provide email']
        ], 423);
    }

    $user = get_user_by_email($email);
	if($user ) {
       
      	
		$name = $user->user_login;
		$email = $user->user_email;
		$adt_rp_key = get_password_reset_key( $user );
		$user_login = $user->user_login;
		$rp_link = '<a href="' . wp_login_url()."?action=rp&key=$adt_rp_key&login=" . rawurlencode($user_login) . '">Reset Link</a>';

		if ($name == "") $name = "There";
		$message = "Hi ".$name.",<br>";
		$message .= "Click here to resset the password for your account: <br>";
		$message .= $rp_link.'<br>';

		
	    $subject = __("Your account on ".get_bloginfo( 'name'));
	    $headers = array();

	   add_filter( 'wp_mail_content_type', function( $content_type ) {return 'text/html';});
	   //  $headers[] = 'From: Your company name <info@your-domain.com>'."\r\n";
	   wp_mail( $email, $subject, $message, $headers);

	   // Reset content-type to avoid conflicts -- http://core.trac.wordpress.org/ticket/23578
	   remove_filter( 'wp_mail_content_type', 'set_html_content_type' );
        wp_send_json_success([
            'result' => [
              
                'message' => 'Your are password reset link has been sent your email.'
            ]
        ]);
    } else {
        // password or user don't match
        wp_send_json_error([
            'errors' => ['Email / password is not correct']
        ], 423);
    }
}, 10, 3);