I’ve made QNAP packages for those who want to run the web GUI on a QNAP NAS:
Marvell ARM: https://acrosync.com/duplicacy-web/duplicacy_web_qnap_arm_x19_1.4.1.qpkg
Mindspeed ARM: https://acrosync.com/duplicacy-web/duplicacy_web_qnap_arm_x31_1.4.1.qpkg
Annapurna Alpine ARM: https://acrosync.com/duplicacy-web/duplicacy_web_qnap_arm_x41_1.4.1.qpkg
AnnapurnaLabs AL324 ARM 64bit: https://acrosync.com/duplicacy-web/duplicacy_web_qnap_arm_64_1.4.1.qpkg
Intel/AMD x86: https://acrosync.com/duplicacy-web/duplicacy_web_qnap_x86_1.4.1.qpkg
Intel/AMD 64bit: https://acrosync.com/duplicacy-web/duplicacy_web_qnap_x86_64_1.4.1.qpkg
Follow this guide to determine the CPU type and then select the corresponding package to install.
If the selected package can be installed and run successfully please post below to let me know. I only have a TS-212 which has a Marvell ARM cpu so only the arm_x19 package has been tested.