Seems like your ESP32 board / card doesn’t have a auto-reset circuit built into it then? The flasher tool (esptool.py) expects to be able to do a reset-into-bootloader mode (that is, pull enable low, pull GPIO0 low, release enable) by using the USB-serial adapter’s DTR and RTS lines (which are usually used for flow-control) as controllable GPIO pins.
The exact expected circuit can e.g. be seen in any ESP32 dev board schematic (example).
So if you’d like to have the comfortable auto-reset / auto program behavior you need to check whether the cards has the above circuitry. If yes, then probably the DTR and RTS lines of the serial adapter (that are hopefully exposed) weren’t properly connected to the card. If it doesn’t have the circuitry, eithehr keep manually resetting the board into bootloader mode or use the two NPN transistors, two resistors and two capacitors per above to add the required circuitry, and connect your serial adapter to it. (The capacitors are also important).