$ret       = '#llms-plan-locked';
		$available = $this->is_available_to_user( get_current_user_id() );

		// if bypassing availability checks OR plan is available to user.
		if ( ! $check_availability || $available ) {

			$ret_params  = array(
				'plan' => $this->get( 'id' ),
			);
			$redirection = $this->get_redirection_url( true, true );
			if ( $redirection ) {
				$ret_params['redirect'] = $redirection;
			}

			$ret = llms_get_page_url( 'checkout', $ret_params );

			// not available to user -- this is a member's only plan.
		} elseif ( ! $available ) {

			$memberships = $this->get_array( 'availability_restrictions' );

			// if there's only 1 plan associated with the membership return that url.
			if ( 1 === count( $memberships ) ) {
				$ret         = get_permalink( $memberships[0] );
				$redirection = $this->get_redirection_url();

				if ( $redirection ) {
					$ret = add_query_arg(
						array(
							'redirect' => $redirection,
						),
						$ret
					);
				}
			}
		}

		/**
		 * Filter the checkout URL for an access plan.
		 *
		 * @since Unknown
		 * @since 3.31.0 The `$check_availability` parameter was added.
		 *
		 * @param string $ret      The checkout URL.
		 * @param LLMS_Access_Plan $this Access plan object.
		 * @param bool             $check_availability Determine if availability checks should be made.
		 *                                             (allows retrieving plans on admin panel)
		 */
		return apply_filters( 'llms_plan_get_checkout_url', $ret, $this, $check_availability );

	}