Power BI: Grouping results in a many to many relationship - powerbi

Question

I am new to power BI, I imported 3 tables from SQL server to Power BI Desktop: 2 main tables and 1 for many to many relationship (bridge), and I need to get results from the second main table based on grouping from the first and second main tables.
Tables are: Customers, Orders, OrderCustomers (bridge table). Orders table has a SalesChannelId field, and I need to get each customer's orders grouped by sales channels, and the percentage of all the customer's orders
I already achieved this with a SQL query (which is the thing I am good at):
select
Customers.FirstName,
all_orders.orders_count,
SalesChannels.Name as SalesChannel,
COUNT(OrderCustomers.OrderId) as SaleChannelOrdersCount,
cast (((COUNT(OrderCustomers.OrderId) * 100) / all_orders.orders_count) as nvarchar(3)) + '%' as SaleChannelOrdersPercent
from
Customers
inner join OrderCustomers
on OrderCustomers.CustomerId = Customers.Id
inner join Orders
on Orders.Id = OrderCustomers.OrderId
inner join SalesChannels
on SalesChannels.Id = Orders.SalesChannelId
inner join
(select
Customers.id as customer_id,
COUNT(OrderCustomers.OrderId) as orders_count
from
Customers
inner join OrderCustomers
on OrderCustomers.CustomerId = Customers.Id
where 1=1
group by Customers.id) as all_orders
on all_orders.customer_id = Customers.Id
where 1=1
group by Customers.id, Customers.FirstName, SalesChannels.Name, all_orders.orders_count
order by Customers.id, SalesChannels.Name
With this query I get results like these:
FirstName orders_count SalesChannel SaleChannelOrdersCount SaleChannelOrdersPercent
Adam 9 Online 1 11%
Adam 9 Counter 8 88%
Henrik 3 Counter 3 100%
Mary 15 Online 3 20%
Mary 15 Counter 12 80%
How to achieve the same results using Power BI?