Hello AdrianaDrgová, welcome to the Microsoft community, I'll be happy to help you today;
I understand that you want to disable ransomware protection;
Access Windows Security;
Click Application and Browser Control;
Click Reputation-based protection settings;
In Potentially unwanted app blocking, disable the option;
If you don't find the feature try the following;
Go to Windows Security and click on Virus and threat protection;
Click on Manage Settings;
Under Controlled Folder Access, click Manage Controlled Folder Access;
Disable "Controlled Access to Folders";
Hope this helps, see you soon!