Average Price Per Share is calculated by dividing the Cost Basis (the amount you have spent to own this stock minus any fees) by the Number of Shares.
If you have only ever bought positions on a stock, the Cost Basis is simply the sum of all your Total Orders minus any FX Fees, if applicable.
However, if you have ever sold positions on a stock, the Cost Basis is calculated based on FIFO (first in, first out) cost queue. As this is calculated by the app, please ask the Customer Support team to supply the Cost Basis of your stock.
The Number of shares can be found under the stock within your 'Investments' section on your Portfolio page.