Online PHP editor | output for KTBkK

Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12: Fatal error: Uncaught ValueError: mb_detect_encoding(): Argument #2 ($encodings) contains invalid encoding "Foo" in /in/KTBkK:2 Stack trace: #0 /in/KTBkK(2): mb_detect_encoding('', 'Foo, UTF-8') #1 {main} thrown in /in/KTBkK on line 2
Process exited with code 255.
Output for 7.2.29 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33: Warning: mb_detect_encoding(): Illegal argument in /in/KTBkK on line 2 string(5) "ASCII" Warning: mb_detect_encoding(): Illegal argument in /in/KTBkK on line 3 string(5) "ASCII"
Output for 7.1.0 - 7.1.20, 7.2.0 - 7.2.8: string(5) "UTF-8" Warning: mb_detect_encoding(): Illegal argument in /in/KTBkK on line 3 string(5) "ASCII"