No, once you have submitted your application you will not be able to make any changes. If you need to update information on the organisation/school such as address, phone numbers, names of legal representatives etc. because they have changed since the submission of the proposal, please send such information to: grants@rycowb.org stating in the subject of the email:
CHANGE OF INFO: RYCO CfP 2019/PROJECT TITLE/CONTRACTING PARTY[1]
However, you can edit your application on the platform as often as you want until the deadline, and make changes online before submitting it.
[1] Contracting Party can be one of the following: Albania, Bosnia and Herzegovina, Kosovo*, Montenegro, Macedonia, or Serbia, according to the seat of the Applicant
* This designation is without prejudice to positions on status, and is in line with UNSCR 1244 and the ICJ Opinion on the Kosovo Declaration of Independence