Amantchi joined National League North side Blyth Spartans on loan in September 2019.[6] He returned to Chesterfield at the end of his loan spell in January 2020,[7] having scored twice in 14 National League North games.[1]
He left Chesterfield in summer 2020 after the club chose not to renew his contract.[8]
After a trial spell at Middlesbrough in September 2020,[1][9] and a single appearance for Workington in a 1–0 win away to Colne,[10][11] Amantchi signed for National League North side Darlington on a non-contract basis on 9 October 2020.[12] He played three games for Darlington in all competitions.[1]
On 27 November 2020, Amantchi rejoined Blyth Spartans on a non-contract basis.[13]
Amantchi returned to Workington on 10 September 2021,[11] but again made just one appearance for the club.[14]