Based on my research, here is my analysis of the claim:

Reasoning:

• The claim states Mbappé was "the top goalscorer" (singular) in the 2024 Champions League with 8 goals¹.
• For the 2023-24 season (which concluded in 2024), Kylian Mbappé scored 8 goals and was tied with Harry Kane for top scorer - he was not the sole top goalscorer¹.
• For the 2024-25 season (ongoing), Mbappé has scored 7 goals in the Champions League, not 8²³.
• The current top scorers for 2024-25 are Serhou Guirassy and Raphinha with 13 goals each, followed by Harry Kane and Robert Lewandowski with 11 goals³.
• Therefore, Mbappé was never the sole top goalscorer with exactly 8 goals - in 2023-24 he was tied with Kane at 8 goals, and in 2024-25 he has only 7 goals.

Overall validity: 0%

1. UEFA Champions League Scoring Stats, 2023-24 Season - ESPN
2. Kylian Mbappé - Stats 24/25 | Transfermarkt - Transfer Market
3. Champions League 2024/2025 » Statistics: Topscorer