By reliable accounts, the safest, easiest land entry from Ecuador into Colombia is at the Rumichaca bridge between Tulcán, Ecuador .. and Ipiales, Colombia. The centers of those two cities are about ten miles apart.
Although the Nariño province of Colombia, which includes Ipiales, has areas that are unsafe due to guerrilla activity, the portion that includes the Rumichaca bridge and the city of Ipiales are safer than those mostly-rural areas.
Andes Transit (andestransit.com), a prominent provider of bus transportation, is providing services besides bus travel itself to assist cross-border travelers, including an information kit (8.99 USD).
However, the company reports that the land borders remain closed (advisory posted March 10, 2021) to prevent covid spread. It says the exception is humanitarian-purposed travel .. for instance, agencies that provide relief supplies to those in need.
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Your OP has no financial connection to Andes Transit or any other company that he may mention in this thread.
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