Problem "There is no custom keyword"

Hello everyone, I have a little problem and I dont have any ideas. I made a custom keyword for uploading file using this manual - Katalon Studio Native Popup Window and Upload File.
When I try to use my keyword in Katalon Studio I get the error “There is no custom keyword” although this keyword was saved in package. Why I get this error and how to fix it?

Currently you have this:

...
public class FirstTable {

    @Keyword
    def FirstTable(TestObject to, String filePath) {
    ... 

The method name should be something different from the containing Class’s name FirstTable. For example:

...
public class FirstTable {

    @Keyword
    def uploadFile(TestObject to, String filePath) {
    ... 

Hi @n.naumchik, once you get your custom keyword working you might want to also check out this link regarding uploading files using ‘sendKeys’ or ‘File Upload’: How-to use ‘sendKeys’ or 'File Upload' to upload files when the //input[@type,'file'] is hidden

I corrected the keyword but the error still appeared. After I use rigt click on section “Keyword” and select “Refresh (F5)” and my keyword work, error not displayed
Thank you!

Thank you!