Depending on the country you are registered from, the availability of the deposit options may vary. To identify which deposit methods are supported by your country of residence, please check out this article: How can I deposit funds to my Shares account?
Adding funds to your Shares account is free of charge.
However, you might be subject to additional charges by your bank when depositing funds in the EU.
Also, if you are making the deposit from a different currency account to your Shares account (please check the available payment methods and currencies here: How can I deposit funds to my Shares account?), you might be subject to currency conversion fees by your bank.