These are Synology packages for installing the Web GUI of Duplicacy on DSM 7.0:
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_alpine_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_apollolake_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_armada370_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_armadaxp_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_avoton_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_braswell_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_broadwell_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_broadwellnk_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_bromolow_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_cedarview_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_denverton_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_geminilake_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_grantley_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_rtd1296_1.5.0.spk
https://acrosync.com/duplicacy-web/duplicacy_web_dsm7.0_v1000_1.5.0.spk
If you need to find out which package is for your Synology NAS, check this page: https://kb.synology.com/en-global/DSM/tutorial/What_kind_of_CPU_does_my_NAS_have
Note: on DSM 7.0 the Web GUI runs as duplicacy
which is a system internal account. If you want to back up a shared folder you’ll need to make that folder readable by duplicacy
.