Your requirements could not be resolved to an installable set of packages.
Problem 1
- Root composer.json requires oxid-solution-catalysts/paypal-client v2.0.16 (exact version match), found oxid-solution-catalysts/paypal-client[dev-main, dev-PSPAYPAL-618_CacheToken, dev-PSPAYPAL-618_CacheToken_6.1, dev-PSPAYPAL-678_Oxid7, dev-PSPAYPAL-685_GooglePay, dev-PSPAYPAL-724_BNCodes, dev-PSPAYPAL-806_UniquePayPalRequestID, dev-b-6.1.x, dev-b-6.3.x, dev-b-7.0.x, v1.0.0, ..., v1.0.10, v2.0.7, ..., v2.0.15, v3.0.8, v3.0.9, v3.0.10, v3.0.11] but it does not match the constraint.