Fair Value of Financial Instruments - Summary of Fair Values Determined Using Black-Scholes Option-Pricing Model (Details)	Sep. 30, 2021	Sep. 30, 2020
Expected Volatility | Minimum
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrants and Rights Outstanding, Measurement Input	78.60	78.35
Expected Volatility | Maximum
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrants and Rights Outstanding, Measurement Input	84.81	87.57
Expected Volatility | Weighted Average
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrants and Rights Outstanding, Measurement Input	82.78	82.22
Dividend Yield
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrants and Rights Outstanding, Measurement Input	0.00	0.00
Risk-Free Interest Rates | Minimum
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrants and Rights Outstanding, Measurement Input	0.34	0.17
Risk-Free Interest Rates | Maximum
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrants and Rights Outstanding, Measurement Input	1.51	0.62
Risk-Free Interest Rates | Weighted Average
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrants and Rights Outstanding, Measurement Input	1.35	0.52
Expected Term | Minimum
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrants and rights outstanding, term	2 years 3 months	3 years 3 months
Expected Term | Maximum
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrants and rights outstanding, term	9 years 10 months 20 days	9 years 7 days
Expected Term | Weighted Average
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrants and rights outstanding, term	8 years 3 months	7 years 9 months 18 days