Amnesty International has about 60 years of experience working worldwide for human rights.
Among their many concerns, they have a long history of opposing the death penalty.
In 2020 they produced this report on death sentences and executions WORLDWIDE:
https://www.amnesty.ca/sites/default/files/Amnesty%20Death%20Sentences%20and%20Executions%202019%20WEB%20-%20EMBARGO%2021%20April.pdf