HOW TO SET SUSTAIN ON PSR E453/463/433 WITHOUT A SUSTAIN PEDAL - YouTube
Universal Sustain Foot Pedal Piano-Style with Polarity Switch 1/4" Input Jack for Digital Piano Electronic Keyboard - Walmart.com
Specs: PSR-EW310 Portable 76-key Keyboard - Yamaha USA
Amazon.com: Amazon Basics Digital Piano 88 Key Semi-Weighted Keyboard with Sustain Pedal, Power Supply, 2 Speakers, and Lesson Mode, Black : Musical Instruments