How to Prune sceptre foxglove?
No pruning required except deadheading to encourage further flowering

sceptre foxglove · Digitalis sceptrum
In frost-free areas, grow in a sheltered position in a sunny to partially shaded site in well-drained soil; in frost-prone areas, grow in a cool greenhouse with minimum night temperatures of 5-10°C, in medium-fertility loam-based compost, such as John Innes No. 2, with added sand and leafmould, water plentifully in summer but moderately in winter, and keep plants well ventilated
No pruning required except deadheading to encourage further flowering