Search for objects by name, containing "+"

Hi, my customer has a number of documents in the vault that have a "+" in their name. Using the REST API, I am unable to find these documents. What is the correct way to pass the "+" character to the search?

Example:

The name of an existing document in the vault is as follows: "3670_099_ZIL_24_test D+M"

The syntax of the REST API call to find the document is as follows:

GET m-files-test.pks.cz/.../objects

The result of the call is empty:

{
    "Items": [],
    "MoreResults": false
}

Thank you for any help, regards from Prague

Jiří