ANTLR treats strings as an unacceptable input alternative

Question

I am still new to ANTLR, but I can’t even run the very normal Hello World program. To get started, here is the corresponding code (I think):

Test.g4

grammar Test;

kod
: påstående ';' kod
| EOF
;

påstående
:skriv
;

skriv
: 'skriv' STR
;


STR:('a'..'z')+ ;
WS: [ \n\t\r]+ -> skip ;

test1.t (My test program)

skriv helloworld;

When I compile and run the RunTest.java file, this is the output in the console:

line 1:0 no viable alternative at input 'skriv'

Process finished with exit code 0

Not sure what is wrong here. I tried various inputs such as numbers, quotation marks, equal signs, etc., but all this gives me the same error.