You can try this code, tested and it worked, it is for child theme.

add_action( 'woocommerce_checkout_process', 'wc_minimum_required_order_amount' );
add_action( 'woocommerce_before_cart' , 'wc_minimum_required_order_amount' );
function wc_minimum_required_order_amount() {

    // HERE Your settings
    $minimum_amount     = 100; // The minimum cart total amount
    $shipping_method_id = 'local_pickup'; // The targeted shipping method Id (exception)

    // Get some variables
    $cart_total     = (float) WC()->cart->total; // Total cart amount
    $chosen_methods = (array) WC()->session->get( 'chosen_shipping_methods' ); // Chosen shipping method rate Ids (array)

    // Only when a shipping method has been chosen
    if ( ! empty($chosen_methods) ) {
        $chosen_method  = explode(':', reset($chosen_methods)); // Get the chosen shipping method Id (array)
        $chosen_method_id = reset($chosen_method); // Get the chosen shipping method Id
    }

    // If "Local pickup" shipping method is chosen, exit (no minimun is required)
    if ( isset($chosen_method_id) && $chosen_method_id === $shipping_method_id ) {
        return; // exit
    }

    // Add an error notice is cart total is less than the minimum required
    if ( $cart_total < $minimum_amount ) {
        $text_notice = sprintf(
            __("The minimum required order amount is %s (your current order amount is %s).", "woocommerce"), // Text message
            wc_price( $minimum_amount ),
            wc_price( $cart_total )
        );
        
        if ( is_cart() ) {
            wc_print_notice( $text_notice, 'error' );
        } else {
            wc_add_notice( $text_notice, 'error' );
        }
    }
}