For replacing Notion Kanban, maybe AFFiNE, that is mostly MIT license:
https://github.com/toeverything/AFFiNE
But some part of server code license may need checking:
https://github.com/toeverything/AFFiNE/blob/canary/packages/...
https://github.com/toeverything/AFFiNE
But some part of server code license may need checking:
https://github.com/toeverything/AFFiNE/blob/canary/packages/...