FAIR VALUE MEASUREMENTS - Schedule of Aggregate Fair Value of Warrants (Details) - Level 3 [Member] - Common Stock Warrant [Member]	3 Months Ended
	Mar. 31, 2025 £ / shares	Mar. 31, 2024 $ / shares	Mar. 31, 2025 $ / shares
Convertible Notes Receivable [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Stock price \| £ / shares	£ 0.000035
Expected term (in years)	1 year 3 months
Expected volatility	157.70%
Risk-free interest rate	4.20%
Expected dividend yield	0.00%
Junior Note Warrants [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Stock price		$ 0.14	$ 0.19
Expected term (in years)		4 years 8 months 12 days
Expected volatility		69.80%
Risk-free interest rate	3.90%	4.20%
Expected dividend yield	0.00%	0.00%
Junior Note Warrants [Member] \| Minimum [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Expected term (in years)	3 years 8 months 12 days
Expected volatility	62.40%
Junior Note Warrants [Member] \| Maximum [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Expected term (in years)	4 years 4 months 24 days
Expected volatility	65.20%
Indigo Capital Convertible Notes [Member] \| Minimum [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Stock price			0.19
Expected term (in years)	11 months 1 day
Indigo Capital Convertible Notes [Member] \| Maximum [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Stock price			$ 0.26
Expected term (in years)	11 months 26 days